Open Access

Synthesis, characterization and in vitro antimicrobial activity of novel fused pyrazolo[3,4-c]pyridazine, pyrazolo[3,4-d]pyrimidine, thieno[3,2-c]pyrazole and pyrazolo[3′,4′:4,5]thieno[2,3-d]pyrimidine derivatives

Chemistry Central Journal201711:112

https://doi.org/10.1186/s13065-017-0339-4

Received: 2 July 2017

Accepted: 19 October 2017

Published: 2 November 2017

Abstract

Background

Some novel substituted pyrazolone, pyrazolo[3,4-c]pyridazine, pyrazolo[3,4-d]pyrimidine, pyrazolo[3,4-d]thiazolo[3,2-a]pyrimidinone, thieno[3,2-c]pyrazole and pyrazolo[3′,4′:4,5]thieno[2,3-d]pyrimidine derivatives have been reported to possess various pharmacological activities like antimicrobial, antitumor and anti-inflammatory.

Results

A novel series of azoles and azines were designed and prepared via reaction of 1,3-diphenyl-1H-pyrazol-5(4H)-one with some electrophilic and nucleophilic reagents. The structures of target compounds were confirmed by elemental analyses and spectral data.

Conclusions

The antimicrobial activity of the target synthesized compounds were tested against various microorganisms such as Escherichia coli; Bacillus megaterium; Bacillus subtilis (Bacterial species), Fusarium proliferatum; Trichoderma harzianum; Aspergillus niger (fungal species) by the disc diffusion method. In general, the novel synthesized compounds showed a good antimicrobial activity against the previously mentioned microorganisms.

Keywords

Substituted pyrazolonePyrimidine derivativesAntimicrobial activity

Background

The compounds containing nitrogen are important category of heterocyclic compounds, which play a significant roles in modern pesticide industry (85% of pesticides with high activity and low toxicity contain nitrogen heterocyclic compound) [1]. Pyrazoles are important moieties as building blocks for many heterocyclic products and act as abinucleophile [2] with abroad spectrum of remarkable biological activities. Many derivatives containing pyrazole nucleus have been commercialized as herbicides, insecticides and fungicides for plant protection [3]. Heterocycles containing a pyrazole or pyrazolone nucleus have been reported to show abroad spectrum of biological activity including antimicrobial [4], anti-cyclooxygenase [5], anti-convulsant [6], antitubercular [7], antitumor [8], anti-inflammatory [9], analgesic [10], antidiabetic [11], antipshycotic [1214]. In last few years, we have been involved in a program aimed at developing new efficient synthetic approaches for the synthesis of heterocyclic compounds of biological interest [1517]. Since most of the pyrazole derivatives show anti-microbial activity, the synthesized compounds are also expected to show antimicrobial activity. Hence, our plan is to synthesize some substituted pyrazole derivatives and subsequently screen for their antimicrobial activity.

Results and discussion

Chemistry

The starting material 4-acetyl-1, 3-diphenyl-1H-pyrazol-5(4H)-one 2 was synthesized from acylation of pyrazolone 1 [18] with acetyl chloride in acetic anhydride and sodium acetate under reflux in good yield [19, 20].

Pyrazol-5-one derivative 2 was exploited as a key intermediate for the synthesis of hitherto unknown fused pyrazole. Thus cyclocondensation of 2 with active methylene reagent such as malononitrile in ethanol under reflux in the presence catalytic amount of piperidine afforded indazole derivative 3 on the basis of analytical and spectral data (Scheme 1). The formation of 3 from the reaction of 2 with malononitrile is believed to be formed via initial condensation of malononitrile with the ring carbonyl and subsequent elimination of water followed by addition of methyl group on the triple bond system of cyano group. Also, compound 2 condensed with aryl aldehyde 4a in ethanol containing 10% sodium hydroxide to afford the condensation product 5 based on its elemental and spectral data (Scheme 1) [21]. Cyclization of 5 with ethyl cyanoacetate in ethanol in the presence of ammonium acetate at reflux temperature led to the formation of dihydropyridine derivative 6 (Scheme 1) [2225]. The reactivity of methyl group in pyrazolone 2 toward aryl diazonium salts was also investigated aiming at preparation of new pyridazine derivatives. Thus, when 2 coupled with aryl diazoniuum salt 7a in ethanol in the presence of sodium acetate yielded hydrazone 8a on the basis on its spectral data. The 1H-NMR spectrum of compound 8a recorded in DMSO-d 6 revealed a signal at δ = 12.00 ppm which could be attributed to hydrazone NH group. Similarly, pyrazolone 2 was coupled readily with aryl diazonium salts 7b in the same reaction conditions to give 8b as demonstrated in (Scheme 1). Compounds 8a–b could be cyclized to the corresponding pyrazolo[3,4-c]pyridazin-4(7H)-one 9a–b upon fusion in domestic microwave oven in the presence of ammonium acetate (Scheme 1) [26, 27].
Scheme 1

Synthesis of pyrazoles 2–9

The foregoing results prompt us to investigate the synthetic potentiality of pyrazolone 1 toward a variety of electrophilic reagents. Thus, when pyrazolone 1 was allowed to react with aryl aldehydes 4a–b to give arylidines 10a–b. The pyrazolopyrimidines 11a–b were obtained by cyclization of pyrazolones 10a–b with thiourea in refluxing ethanol containing 10% potassium hydroxide (Scheme 2). The formation of pyrazolopyrimidinethione 11 is believed to be formed via initial condensation of thiourea with the carbonyl group of 10 and subsequent elimination of water followed by addition NH2 of thiourea on the double bond system of 10 [21, 2831]. Pyrazolopyrimidinethiones 11a–b was used as building blocks for the synthesis of condensed heterocycles. Thus, when pyrazolopyrimidinethione 11a is allowed to react with chloroacetic acid in refluxing acetic acid in the presence of sodium acetate furnished pyrazolo[3,4-d]thiazolo[3,2-a]pyrimidine derivative 12a in a quantitative yield (Scheme 2). Similarly, pyrazolopyrimidinethione 11b reacted with chloroacetic acid in the same reaction condition to give pyrazolo[3,4-d]thiazolo[3,2-a]pyrimidine derivative 12b (Scheme 2) [3234]. Diphenylpyrazolone 1 was oxidized by exposing it to air to give 4-(5-oxo-1, 3-diphenyl-1H-pyrazol-4(5H)-ylidene)-1,3-diphenyl-1H-pyrazol-5-one 13 (scheme 2) [35].
Scheme 2

Synthessis of pyrazoles 10–13

As an extension to Gewald synthesis of thiophene and fused thiophene, a mixture of diphenyl pyrazolone 1, cyanoacetic acid hydrazide and elemental sulfur in DMF containing a catalytic amount of piperidine is refluxed to yield 5-amino-1,3-diphenyl-1H-thieno[3,2-c]pyrazole-6-carbohydrazide 14 based on its elemental and spectral data (Scheme 3) [36].
Scheme 3

Synthesis of pyrazoles 14–19

Hydrazide 14 is used as a key precursor for many chemical transformations to synthesize a variety of important heterocycles. Thus, when compound 14 was allowed to react with triethylorthoformate in refluxing acetic anhydride afforded 5-amino-1,3-diphenyl-1H-thieno[3,2-c]pyrazole-6-(N-ethoxymethylene-carbohydrazide) 15 (Scheme 3). Fusion of 15 afforded 6-(1,3,4-oxadiazol-2-yl)-1,3-diphenyl-1H-thieno[3,2-c]pyrazol-5-amine 16. Establishing structure of 16 was based on its elemental and spectral data. For example the infrared spectrum of thienopyrazole 16 revealed the absence of carbonyl group. The 1H-NMR of the same product revealed absence of signals of ethyl fragment. The mass spectrum showed a very intense molecular ion peak at 361 (M++2) and a number of fragments support the proposed structure [37]. Treatment of 14 with benzoyl chloride 17 afforded 5-amino-N′-benzoyl-1,3-diphenyl-1H-thieno[3,2-c]pyrazole-6-carbohydrazide 18 on the basis of its elemental analysis and spectral data. Moreover, the reaction of 18 with triethylorthoformate at reflux temperature afforded the fused pyrimidine derivative 19 (Scheme 3) [38].

The behavior of thienopyrazole 14 toward active methylene reagents was also investigated. Thus, thienopyrazole 14 was reacted with malononitrile in refluxing ethanol containing catalytic amount of piperidine to yield 3-amino-5-(5-amino-1,3-diphenyl-1H-thieno[3,2-c]pyrazol-6-yl)-1H-pyrazole-4-carbonitrile 20 (Scheme 4). The formation of 20 is believed to be formed via condensation of malononitrile with carbonyl group of 14 followed by addition of amino group on the cyano group of malononitrile and subsequent cyclization to give 20. Also thienopyrazole 14 reacted with acetylacetone in refluxing ethanol to afford 5-amino-1,3-diphenyl-1H-thieno[3,2-c]pyrazol-6-yl)(3,5-dimethyl-1H-pyrazol-1-yl)methanone 21 based on its elemental and spectral data (Scheme 4). Furthermore, treatment of compound 14 with aryl aldehydes 4a–b yielded arylmethylene hydrazide derivatives 22a–b in quantitative yields [39]. Acylation of 22a–b using acetic anhydride under reflux afforded 23a–b which undergoes cyclization upon refluxing in sodium ethoxide to afford the pyrazolo[3′,4′:4,5]thieno[2,3-d]pyrimidinone derivative 24 (Scheme 4) [37]. Finally, compound 14 was treated with carbon disulphide in refluxing ethanol/sodium hydroxide solution to afford the promising compound 7-amino-1,3-diphenyl-6-thioxo-1,5,6,7-tetrahydro-8H-pyrazolo[3′,4′:4,5]thieno [2,3-d]pyrimidin-8-one 25 (Scheme 4). Establishing structure 25 was based on its elemental and spectral data.
Scheme 4

Synthesis of pyrazoles 20–24

Antimicrobial activity

The newly synthesized compounds and their derivatives have been screened for antibacterial activity against some gram negative bacteria (Escherichia coli) and some gram positive bacteria (Bacillus megaterium and Bacillus subtilis), and antifungal activity against Fusarium proliferatum, Trichoderma harzianum and Aspergillus niger, by the cup-plate method and agar diffusion disc method for determining MIC (minimum inhibitory concentration), ampicillin and colitrimazole were used as standards for comparison of antibacterial and antifungal activity, respectively.

The anti-bacterial activity of the synthesized compounds was tested against bacterial species (E. coli; B. megaterium; B. subtilis) and the antifungal activity was tested also against fungal species (F. proliferatum; T. harzianum; A. niger). Each compound was dissolved in DMF, About 100 mL of each compound will be pipetted and poured into the cups existed in nutrient agar plates containing medium which consisted of: peptic digest of animal tissue 5.00, sodium chloride 5.00, Beef extract 1.50, Yeast extract 1.50, Agar 15.00 all in gm/L, final pH at 25 °C; 7.4 ± 0.2) or Czapek’s agar plates for fungi (sucrose 30.00, sodium nitrate 2.00, dipotassium phosphate 1.00, magnesium sulphate 0.50, potassium chloride 0.50, ferrous sulphate 0.01, Agar 15.00, all in gm/L, final pH at 25 °C; 7.3 ± 0.2), seeded with E. coli, B. megaterium and B. subtilis, F. proliferatum, T. harzianum and A. niger, respectively.

For determining minimum inhibitory concentration (MIC), serial dilutions of tested compounds (μg/mL) as well as reference antibiotics were prepared using 10% DMF solution, paper discs of Whatman filter paper were prepared with standard size (8 mm), were cut and sterilized in an autoclave. The paper discs soaked in the desired compound solution were placed aseptically in the petri dishes containing agar media and microbial species. The petri dishes were incubated at 36–37 °C and the inhibition zones were recorded after 24 h of incubation in case of bacteria and after 5–7 days in case of fungi. Each treatment was replicated three times [40, 41]. The antibacterial activity of a common standard antibiotic ampicillin and antifungal Clotrimazole was also recorded using the same procedure as above at the same concentration and solvents. The % activity index for the compound was calculated by the following formula.
$$\% {\text{ Activity index }} = \frac{{{\text{Zone of inhibition by test compound }}\left( {\text{diameter}} \right)}}{{{\text{Zone of inhibition by standard }}\left( {\text{diameter}} \right) \times \; 100}}$$
Our results showed that most of checked compounds were active against most of micro-organisms used, while the discs which containing DMF solution (10%) alone were not exhibited any effect on the growing micro-organisms (no inhibition zone around the discs). The results of antimicrobial and antifungal activity and its MIC are illustrated in Tables 1, 2. We found that compounds; 3, 13, 2, 12a and 20 showed promising broad spectrum antibacterial activities against E. coli. Compounds 14, 12b, 15, 2 and 24 showed maximum antimicrobial activity against B. megaterium, B. subtilis, F. proliferatum, T. harzianum and A. niger, respectively. Compounds; 9b, 8b, 6, 22a, 5a, 11b, 18 and 16 demonstrated moderate antimicrobial activity against gram positive, gram negative bacteria and fungi. On the other hand, 10a, 10b, 11a, 23a, 25 and 23b exhibited low antibacterial activity and moderate to low antifungal activity, whereas 25 and 23b showed high antibacterial activity against only B. subtilis. From Table 2, we observed that compounds; 13, 6, 3 and 14 showed the minimum inhibitory concentrations (MIC) for most tested bacteria and fungi, while compounds; 9b, 8b, 22a, 5a, 11b, 18 and 19 exhibited high concentrations of MIC as compared with standard antimicrobial agents used.
Table 1

Antibacterial and antifungal activities of synthesized compound

Compounds

Bacterial species

Fungal species

Escherichia coli

Bacillus megaterium

Bacillus subtilis

Fusarium proliferatum

Trichoderma harzianum

Aspergillus niger

Inhibition zone diameter (mm)

% activity index

Inhibition zone diameter (mm)

% activity index

Inhibition zone diameter (mm)

% activity index

Inhibition zone diameter (mm)

% activity index

Inhibition zone diameter (mm)

% activity index

Inhibition zone diameter (mm)

% activity index

10a

10

43.48

10

43.48

15

65.22

10

45.45

12

54.55

15

68.18

10b

10

43.48

NA

0.00

15

65.22

12

54.55

12

54.55

10

45.45

11a

10

43.48

10

43.48

NA

0.00

12

54.55

15

68.18

15

68.18

11b

12

52.17

NA

0.00

NA

0.00

NA

0.00

10

45.45

12

54.55

2

15

65.22

12

52.17

NA

0.00

12

54.55

15

68.18

12

54.55

12a

15

65.22

10

43.48

20

86.96

12

54.55

12

54.55

10

45.45

12b

10

43.48

NA

0.00

20

86.96

10

45.45

12

54.55

NA

0.00

8b

10

43.48

10

43.48

20

86.96

12

54.55

10

45.45

15

68.18

3

20

86.96

12

52.17

20

86.96

15

68.18

10

45.45

12

54.55

5a

NA

0.00

NA

0.00

12

52.17

15

68.18

NA

0.00

10

45.45

6

NA

0.00

12

52.17

12

52.17

15

68.18

NA

0.00

NA

0.00

9b

NA

0.00

10

43.48

20

86.96

10

45.45

12

54.55

NA

0.00

13

20

86.96

12

52.17

20

86.96

12

54.55

15

68.18

12

54.55

18

10

43.48

10

43.48

20

86.96

20

90.91

12

54.55

15

68.18

22a

12

52.17

NA

0.00

12

52.17

15

68.18

NA

0.00

10

45.45

20

15

65.22

10

43.48

15

65.22

20

90.91

10

45.45

15

68.18

23a

10

43.48

12

52.17

15

65.22

15

68.18

NA

0.00

12

54.55

23b

12

52.17

12

52.17

20

86.96

12

54.55

10

45.45

0

0.00

25

10

43.48

NA

0.00

20

86.96

10

45.45

10

45.45

0

0.00

24

12

52.17

10

43.48

20

86.96

12

54.55

NA

0.00

15

68.18

15

12

52.17

10

43.48

20

86.96

20

90.91

12

54.55

15

68.18

21

12

52.17

NA

0.00

12

52.17

12

54.55

10

45.45

12

54.55

16

10

43.48

10

43.48

15

65.22

12

54.55

NA

0.00

12

54.55

14

12

52.17

15

65.22

20

86.96

NA

0.00

0

0.00

12

54.55

19

NA

0.00

NA

0.00

15

65.22

15

68.18

10

45.45

0

0.00

Ampicillin (antibacterial standard)

23

100.0

23

100.00

23

100.00

Colitrimazole (antifungal standard)

22

100.0

22

100.00

22

100.00

Table 2

Minimum inhibitory concentrations (MIC) for tested compounds

Compounds

Minimum inhibitory concentration (MIC) of the synthesized compounds (µg/mL)

Bacterial species

Fungal species

Escherichia coli

Bacillus subtilis

Bacillus megaterium

Fusarium proliferatum

Trichoderma harzianum

Aspergillus niger

10a

NA

NA

5.10

10.20

25.51

5.10

10b

NA

NA

1.71

21.43

21.43

NA

11a

NA

NA

23.45

46.90

23.45

23.45

11b

14.84

NA

14.84

14.84

29.67

29.67

2

33.47

33.47

33.47

33.47

33.47

5.36

12a

36.22

36.22

5.80

36.22

72.45

NA

12b

29.18

NA

14.59

NA

29.18

NA

8b

87.76

29.20

7.02

43.88

87.76

43.88

3

NA

87.75

NA

5.71

35.71

35.71

5a

NA

NA

NA

35.49

NA

NA

6

NA

71.43

35.71

35.71

NA

NA

9b

54.69

54.69

4.38

4.38

54.69

54.69

13

4.08

10.00

4.08

NA

8.16

8.16

18

58.16

NA

29.08

29.08

29.08

4.65

22a

30.61

NA

NA

30.61

NA

30.61

20

43.47

86.94

43.47

86.94

NA

86.94

23a

NA

83.67

41.84

41.84

NA

6.69

23b

28.78

57.55

4.60

28.78

57.55

4.60

25

66.33

132.65

66.33

132.65

NA

10.61

24

77.14

77.14

6.17

NA

NA

6.17

15

37.96

NA

18.98

NA

37.96

18.98

21

31.84

NA

15.92

NA

NA

15.92

16

47.96

NA

23.98

NA

NA

3.84

14

21.22

21.22

3.40

42.45

42.45

21.22

19

NA

90.20

45.10

7.22

NA

7.22

NA no activity

Experimental section

Chemistry

The melting points, the elemental analysis and the spectral data were recorded as reported in references [19].

Synthesis of 4-acetyl-1,3-diphenyl-1H-pyrazol-5(4H)-one (2). A mixture of pyrazolone 1 (0.01 mol) and acetyl chloride (0.01 mol) in acetic anhydride (10 mL) and sodium acetate (2 gm) was heated under reflux for 9 h. The reaction mixture was allowed to cool and poured into crushed ice then acidified with HCl. The separated solid was filtered, washed with water and crystallized from ethanol to give white crystals; yield (88%); m.p. 111–113 °C. IR (KBr, cm−1) νmax = 3062 (CH-arom), 2956 (CH-aliph), 1706, 1690 (2CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 1.91 (s, 3H, CH3), 2.32 (s, 1H, CH-pyrazole), 7.37–8.14 (m, 10H, aromatic H). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 27.0, 58.1, 121.6, 121.6, 125.8, 126.1, 126.1, 127.3, 127.3, 127.9, 127.9, 128.8, 135.0, 137.2, 151.3, 161.9, 200. MS (EIMS) m/z: 278 (M+, 1), 276 (18), 268 (22), 236 (63), 161 (29), 134 (23), 128 (84), 127 (11), 103 (60), 91 (65), 77 (100), 51 (21). Anal. Calcd. for C17H14N2O2 (278): C, 73.37; H, 5.07; N, 10.07. Found: C, 73.44; H, 5.12; N, 10.19%.

Synthesis of 6-amino-4-oxo-1,3-diphenyl-4,7-dihydro-1H-indazole-7-carbonitrile (3). A mixture of 2 (0.01 mol), malononitrile (0.01 mol) in ethanol (30 mL) containing catalytic amount of piperidine was heated under reflux for 24 h. The reaction mixture was allowed to cool and poured into crushed ice then acidified with HCl. The separated solid was filtered, washed with water and crystallized from ethanol to give brawn crystals; yield (80%); m.p. 170–172 °C. IR (KBr, cm−1) νmax = 3447, 3400 (NH2), 3058 (CH-arom), 2952 (CH-aliph), 2192 (CN), 1700 (CO) cm−1. 1H-NMR (400 MHz, DMSO-d 6 ) δ (ppm): 3.63 (s, 1H, CH), 6.02 (s, 1H, = CH), 7.25–7.92 (m, 10H, aromatic H), 11.81 (s, 2H, NH2). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 33.1, 108.4, 109.2, 113.8, 123.8, 123.8, 124.2, 125.5, 125.5, 127.6, 128, 128, 128.3, 128.3, 131, 139.7, 141.1, 150.8, 158.5, 180.6. MS (EIMS) m/z: 327 (M++1, 0.2), 236 (40), 194 (5), 131 (4), 103 (61), 91 (53), 77 (100), 64 (27), 51 (32). Anal. Calcd. for C20H14N4O (326): C, 73.61; H, 4.32; N, 17.17. Found: C, 73.63; H, 4.34; N, 17.19%.

Synthesis of 4-(3-(4-chlorophenyl)acryloyl)-1,3-diphenyl-1H-pyrazol-5(4H)-one (5). A mixture of 2 (0.01 mol), 4-chlorobenzaldehyde 4a (0.01 mol) and 10% aqueous sodium hydroxide (10 mL) in ethanol (50 mL) was stirred at room temperature for about 3 h. The reaction mixture poured into crushed ice then acidified with HCl. The resulting solid was filtered off, washed with water, dried and crystallized from ethanol to give pale yellow crystals; yield (86%); m.p. 170–172 °C. IR (KBr, cm−1) νmax = 3060 (CH-arom), 2951 (CH-aliph), 1712, 1692 (2CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 3.34 (s, 1H, CH-pyrazole), 5.24 (d, 1H, = CH), 6.01 (d, 1H, = CH), 7.20–8.54 (m, 14H, aromatic H). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 53.6, 123.0, 123.0, 125.3, 127.7, 127.7, 127.8, 128.0, 128.0, 128.0, 128.0, 128.6, 128.6, 129.1, 129.1, 130.2, 130.2, 130.8, 135.0, 137.7, 140.5, 152.6, 166.3, 198.6. MS (EIMS) m/z: 400 (M+, 0.1), 358 (20), 247 (20), 225 (8), 189 (7), 103 (13), 91 (17), 80 (100), 64 (79), 51 (19). Anal. Calcd. for C24H17ClN2O2 (400): C, 71.91; H, 4.27; N, 6.99. Found: C, 71.86; H, 4.20; N, 6.91%.

Synthesis of 4-(4-chlorophenyl)-2-oxo-6-(5-oxo-1,3-diphenyl-4,5-dihydro-1H-pyrazol-4-yl)-1,2-dihydropyridine-3-carbonitrile (6). A mixture of 5 (0.01 mol), ethylcyanoacetate (0.01 mol) in ethanol (30 mL) containing ammonium acetate (2 gm) was heated under reflux for 24 h. The reaction mixture was allowed to cool and poured onto crushed ice then acidified with HCl. The separated solid was filtered, washed with water and crystallized from ethanol to give pale yellow crystals; yield (84%); m.p. 230–232 °C. IR (KBr, cm−1) νmax = 3420 (NH), 3061 (CH-arom), 2926 (CH-aliph), 2208 (CN), 1708 (CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 2.30 (s, 1H, CH-pyrazole), 6.82–8.09 (m, 15H, aromatic H), 9.20 (s, 1H, NH). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 55.1, 101.5, 114.2, 117.8, 123.5, 123.5, 127.2, 127.2, 127.7, 127.7, 127.8, 127.8, 127.8, 127.8, 128.3, 129.1, 129.1, 130.2, 131.6, 131.8, 132.9, 135.2, 136.2, 156.1, 160.5, 164.9, 168.1. MS (EIMS) m/z: 466 (M++2, 0.03), 360 (9), 235 (8), 206 (2), 125 (100), 115 (14), 102 (15), 91 (26), 77 (97), 64 (14), 51 (26). Anal. Calcd. for C27H17ClN4O2 (464): C, 69.75; H, 3.69; N, 12.05. Found: C, 69.81; H, 3.80; N, 12.11%.

General procedure for the synthesis of hydrazono derivatives (8a–b). To a stirred cold solution of aryldiazonium chlorides 7a–b (0.01 mol), prepared by treating aniline derivatives (0.01 mol) with sodium nitrite (0.01 mol) in HCl, ethanol (30 mL) and catalytic amount of sodium acetate, the active methyl reagent 2 was added gradually. The stirring was continued for 2 h. The solid product so formed was filtered off, washed with water several times, dried and crystallized from the proper solvent to afford 8a–b.

4-(2-(2-(4-Chlorophenyl)hydrazono)acetyl)-1,3-diphenyl-1H-pyrazol-5(4H)-one (8a). It was obtained as an orange crystals from ethanol; yield (95%); m.p. 170–172 °C. IR (KBr, cm−1) νmax = 3440 (NH), 3066 (CH-arom), 2927 (CH-aliph), 1772, 1690 (2CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 2.32 (s, 1H, CH-pyrazole), 6.01 (s, 1H, = CH), 6.82–8.14 (m, 14H, aromatic H), 12.00 (s, 1H, NH). MS (EIMS) m/z: 418 (M++2, 0.2), 416 (0.2), 374 (38), 263 (15), 235 (18), 129 (26), 99 (19), 77 (100), 64 (19), 51 (23). Anal. Calcd. for C23H17ClN4O2 (416): C, 66.27; H, 4.11; N, 13.44. Found: C, 66.32; H, 4.17; N, 13.49%.

4-(2-(2-(4-Methoxyphenyl)hydrazono)acetyl)-1,3-diphenyl-1H-pyrazol-5(4H)-one (8b). It was obtained as red crystals from ethanol; yield (92%); m.p. 188–190 °C. IR (KBr, cm−1) νmax = 3440 (NH), 3057 (CH-arom), 2928 (CH-aliph), 1720, 1655 (2CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 2.25 (s, 1H, CH-pyrazole), 3.62 (s, 3H, OCH3), 6.02 (s, 1H, = CH), 7.25–7.84 (m, 14H, aromatic H), 11.80 (hump, 1H, NH). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 53.5, 54.7, 114.2, 114.2, 115.8, 115.8, 123.7, 123.7, 127, 127.1, 127.1, 127.8, 127.8, 127.8, 127.8, 130.1, 133, 133.7, 134.6, 137.4, 154.7, 155.4, 170.1, 201.6. MS (EIMS) m/z: 412 (M+, 0.1), 370 (42), 122 (100), 107 (11), 91 (20), 77 (89), 51 (25). Anal. Calcd. for C24H20N4O3 (412): C, 69.89; H, 4.89; N, 13.58. Found: C, 69.80; H, 4.86; N, 13.51%.

General procedure for the synthesis of pyrazolopyridazinone derivatives (9a–b). A mixture of 8a–b (0.01 mol) and ammonium acetate (2.0 gm) was fused for 3.0 min in domestic microwave. The reaction mixture was left to stand, and then triturated with ethanol; the solid product so formed was collected by filtration and crystallized from the proper solvent to give 9a–b.

7-(4-Chlorophenyl)-1, 3-diphenyl-1H-pyrazolo [3,4-c] pyridazin-4(7H)-one (9a). It was obtained as an orange crystals from ethanol; yield (95%); m.p. 170–172 °C. IR (KBr, cm−1) νmax = 3061 (CH-arom), 1653 (CO) cm−1. 1H-NMR (400 MHz, DMSO-d 6 ) δ (ppm): 7.26–8.17 (m, 15H, aromatic H and CH-pyridazine). MS (EIMS) m/z: 398 (M+, 0.01), 354 (74), 353 (8), 325 (2), 263 (9), 235 (14), 167 (5), 129 (21), 91 (45), 77 (100), 51 (20). Anal. Calcd. for C23H15ClN4O (398): C, 69.26; H, 3.79; N, 14.05. Found: C, 69.30; H, 3.86; N, 14.10%.

7-(4-Methoxyphenyl)-1,3-diphenyl-1H-pyrazolo[3,4-c]pyridazin-4(7H)-one (9b). It was obtained as red crystals from ethanol; yield (92%); m.p. 188–190 °C. IR (KBr, cm−1) νmax = 3059 (CH-arom), 2927 (CH-aliph), 1654 (CO) cm−1. 1H-NMR (400 MHz, DMSO-d 6 ) δ (ppm): 3.81 (s, 3H, OCH3), 6.01 (s, 1H, =CH-pyridazine), 6.94–8.19 (m, 14H, aromatic H). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 53.6, 91.8, 114.8, 114.8, 116.2, 116.2, 120.6, 120.6, 124.2, 126.5, 126.5, 127.8, 128.3, 128.3, 128.6, 128.6, 130.7, 137.8, 138.2, 140.0, 142.4, 148.1, 154.0, 166.5. MS (EIMS) m/z: 394 (M+, 0.1), 338 (2), 236 (40), 207 (5), 167 (2), 128 (21), 115 (10), 103 (53), 91 (57), 77 (100), 64 (91), 51 (16). Anal. Calcd. for C24H18N4O2 (394): C, 73.08; H, 4.60; N, 14.20. Found: C, 73.11; H, 4.67; N, 14.20%.

General procedure for the synthesis of 1, 3-diphenyl pyrazolone derivatives (10a–b). A mixture of diphenyl pyrazolone 1 (0.01 mol), appropriate aryl aldehydes 4a–b (0.01 mol) in ethanol (30 mL) with catalytic amount of piperidine was heated under reflux for 3 h. The reaction mixture was allowed to cool and poured into crushed ice then acidified with HCl. The separated solid was filtered, washed with water and crystallized from an approper solvent to give 10a–b.

4-(4-Chlorobenzylidene)-1,3-diphenyl-1H-pyrazol-5(4H)-one (10a). It was obtained as pale yellow crystals from ethanol; yield (80%); m.p. 215–217 °C. IR (KBr, cm−1) νmax = 3090 (CH-arom), 1676 (CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 5.14 (s, 1H, CH-oleffinic), 7.11–8.03 (m, 14 H, aromatic H). MS (EIMS) m/z: 360 (M++2, 14), 358 (44), 357 (19), 247 (53), 246 (12), 236 (42), 189 (14), 103 (37), 102 (18), 90 (38), 83 (13), 77 (100), 76 (52), 50 (23). Anal. Calcd. for C22H15N2OCl (358): C, 73.64; H, 4.21; N, 7.81. Found: C, 73.69; H, 4.27; N, 7.88%.

4-(4-Hydroxybenzylidene)-1, 3-diphenyl-1H-pyrazol-5(4H)-one (10b). It was obtained yellow crystals from ethanol; yield (78%); m.p. 212–214 °C. IR (KBr, cm−1) νmax = 3448 (OH), 3057 (CH-arom), 1638 (CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 5.09 (s, 1H, CH-oleffinic), 6.58–8.02 (m, 15H, aromatic H and OH). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 114.7, 114.7, 117.2, 117.2, 123.9, 124.3, 127.1, 127.8, 127.8, 127.8, 127.8, 128.7, 128.7, 130.3, 131.5, 131.5, 136.8, 143, 145.1, 154.5, 158.6, 168.2. MS (EIMS) m/z: 340 (M+, 100), 339 (36), 248 (15), 247 (62), 207 (57), 178 (14), 91 (27), 77 (72), 64 (15), 51 (36). Anal. Calcd. for C22H16N2O2 (340): C, 77.63; H, 4.74; N, 8.23. Found: C, 77.65; H, 4.77; N, 8.28%.

General procedure for the Synthesis of pyrazolopyrimidinethione derivatives (11a–b). To boiling solution of compounds 10a–b (0.01 mol) in ethanolic potassium hydroxide (30 mL, 10%), thiourea (0.01 mol) was added. The reaction mixture was refluxed for 20 h, then allowed to cool and poured into crushed ice then acidified with HCl. The separated solid was filtered, washed with water and crystallized from the proper solvent to give 11a–b.

4-(4-Chlorophenyl)-1, 3-diphenyl-4, 5-dihydro-1H-pyrazolo [3,4-d] pyrimidine-6(7H)-thione (11a). It was obtained as pale yellow crystals from ethanol/water; yield (76%); m.p. 136–138 °C. IR (KBr, cm−1) νmax = 3447, 3400 (2NH), 3057 (CH-arom), 2929 (CH-aliph) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 6.01 (s, 1H, CH-pyrimidine), 6.98–7.92 (m, 16H, aromatic H + 2NH). MS (EIMS) m/z: 418 (M++2, 16), 416 (24), 371 (18), 324 (36), 302 (31), 271 (61), 244 (43), 225 (22), 171 (24), 95 (49), 81 (78), 67 (52), 57 (100), 55 (55). Anal. Calcd. for C23H17ClN4S (416): C, 66.26; H, 4.11; N, 13.44. Found: C, 66.20; H, 4.01; N, 13.37%.

4-(4-Hydroxyphenyl)-1, 3-diphenyl-4, 5-dihydro-1H-pyrazolo [3,4-d] pyrimidine-6(7H)-thione (11b). It was obtained as yellow crystals from ethanol/water; yield (79%); m.p. 137–139 °C. IR (KBr, cm−1) νmax = 3576 (OH), 3434, 3400 (2NH), 3055 (CH-arom), 2953 (CH-aliph) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 6.01 (s, 1H, CH-pyrimidine), 6.69–7.83 (m, 17H, aromatic H, 2NH and OH). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 54.8, 107, 114.6, 114.6, 122.3, 122.3, 127.1, 127.1, 127.8, 128.2, 128.2, 128.2, 129, 129, 130.1, 130.1, 131.2, 134, 140.2, 146.3, 149.3, 157, 180.3. MS (EIMS) m/z: 398 (M+, 0.2), 236 (74), 194 (10), 149 (6), 123 (10), 103 (58), 91 (56), 77 (100), 69 (82), 57 (84), 51 (31). Anal. Calcd. for C23H18N4OS (398): C, 69.32; H, 4.55; N, 14.06. Found: C, 69.36; H, 4.60; N, 14.12%.

General procedure for the synthesis of pyrazolo[3,4-d] thiazolo[3,2-a]pyrimidinone derivatives (12a–b). A mixture of 11a–b (0.01 mol), chloroacetic acid (0.01 mol) and anhydrous sodium acetate (1.6 g) in acetic acid (30 mL) and acetic anhydride (10 mL) was refluxed for 3 h. The reaction mixture was poured into water. The separated solid was filtered off and crystallized from an approper solvent to give 12a–b.

4-(4-Chlorophenyl)-1,3-diphenyl-4,7-dihydropyrazolo[3,4-d]thiazolo[3,2-a]pyrimidin-6(1H)-one (12a). It was obtained as pale yellow crystals from benzene; yield (91%); m.p. 148–150 °C. IR (KBr, cm−1) νmax = 3061 (CH-arom), 2928 (CH-aliph), 1709 (CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 5.10 (s, 2H, CH2), 5.90 (s, 1H, CH-pyrimidine), 7.10–8.03 (m, 14H, aromatic H). MS (EIMS) m/z: 456 (M+, 0.3), 236 (13), 194 (3), 125 (4), 91 (33), 77 (100), 63 (78), 51 (25). Anal. Calcd. for C25H17ClN4OS (456): C, 65.71; H, 3.75; N, 12.26. Found: C, 65.75; H, 3.79; N, 12.30%.

4-(4-Hydroxyphenyl)-1,3-diphenyl-4,7-dihydropyrazolo[3,4-d]thiazolo[3,2-a]pyrimidin-6(1H)-one (12b). It was obtained as brown crystals from benzene; yield (82%); m.p. 152–154 °C. IR (KBr, cm−1) νmax = 3438 (OH), 3061 (CH-arom), 2919 (CH-aliph), 1713 (CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 5.10 (s, 2H, CH2), 6.00 (s, 1H, CH-pyrimidine), 7.00–8.20 (m, 14H, aromatic H), 9.20 (hump, 1H, OH). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 29.2, 43.8, 114.1, 114.1, 115.4, 121.0, 121.6, 121.6, 125.1, 126.3, 126.3, 127.6, 127.6, 128.1, 128.1, 128.1, 128.3, 128.3, 130.3, 131.8, 138.6, 147.6, 155.3, 160.2, 177.0. MS (EIMS) m/z: 438 (M+, 0.04), 215 (2), 138 (9), 123 (19), 101 (15), 87 (64), 63 (100), 58 (63), 51 (7). Anal. Calcd. for C25H18N4O2S (438): C, 68.48; H, 4.14; N, 12.78. Found: C, 68.41; H, 4.11; N, 12.71%.

Synthesis of 4-(5-oxo-1, 3-diphenyl-1H-pyrazol-4-(5H)-ylidene)-1,3-diphenyl-1H-pyrazol-5-one (13). To a stirred solution of pyrazolone 1 (0.5 gm) in acetic acid (20 mL), sodium nitrite solution (0.02 mol) in water (5 mL) was added dropwise over 10 min. The solid product was collected and recrystallized from ethanol to give orange crystals; yield (88%); m.p. 180–182 °C. IR (KBr, cm−1) νmax = 3092 (CH-arom), 1700, 1690 (2CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 7.23–8.06 (m, 20H, aromatic H). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 116.4, 116.4, 116.4, 116.4, 127.2, 127.2, 127.8, 127.8, 127.8, 127.8, 127.8, 127.8, 127.8, 127.8, 128.3, 128.3, 128.3, 128.3, 136.8, 136.8, 130, 130, 141.2, 141.2, 144.9, 144.9, 156.5, 156.5, 167, 167. MS (EIMS) m/z: 470 (M++2, 0.07), 265 (61), 220 (25), 167 (5), 129 (29), 115 (14), 91 (29), 77 (100), 51 (32). Anal. Calcd. for C30H20O2N4 (468): C, 76.91; H, 4.30; N, 11.96. Found: C, 76.97; H, 4.35; N, 11.99%.

Synthesis of 5-amino-1,3-diphenyl-1H-thieno[3,2-c]pyrazole-6-carbohydrazide (14). A mixture of diphenylpyrazolone 1 (0.01 mol), cyanoacetohydrazide (0.01 mol) and sulfur (0.01 mol) in DMF (50 mL) containing catalytic amount of piperidine was heated under reflux for 12 h. The reaction mixture was allowed to cool and poured into crushed ice then acidified with HCl. The separated solid was filtered, washed with water and crystallized from DMF/EtOH to give yellow crystals; yield (78%); m.p. 300–302 °C. IR (KBr, cm−1) νmax = 3383, 3292 (2NH2), 3169 (NH), 3063 (CH-arom), 1663 (CO) cm−1. 1H 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 6.00 (s, 2H, NH2), 7.19–7.91 (m, 12H, aromatic H and NH2), 11.20 (hump, 1H, NH). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 104.3, 124.1, 124.1, 125.1, 125.8, 126.5, 126.5, 127.6, 128.6, 128.6, 128.8, 128.8, 131.8, 138.6, 140.9, 163.6, 165.8, 166.8. MS (EIMS) m/z: 351 (M++2, 20), 349 (24), 333 (24), 310 (32), 282 (26), 240 (18), 204 (33), 190 (21), 168 (20), 114 (100), 84 (30), 70 (42), 57 (54), 53 (23). Anal. Calcd. for C18H15N5OS (349): C, 61.87; H, 4.33; N, 20.04. Found: C, 61.92; H, 4.37; N, 20.10%.

Synthesis of 5-amino-1,3-diphenyl-1H-thieno[3,2-c]pyrazole-6-(N-ethoxymethylene-carbohydrazide) (15). A mixture of 14 (0.01 mol) and triethylorthoformate (5 mL) in acetic anhydride (10 mL) was heated under reflux for 6 h. The reaction mixture was allowed to cool and poured into crushed ice. The separated solid was filtered, washed with water and crystallized from ethanol to give brown crystals; yield (60%); m.p. 110–112 °C. IR (KBr, cm−1) νmax = 3454, 3400 (NH2/NH), 3061 (CH-arom), 2979–2852 (CH-aliph), 1661 (CO) cm−1. 1H-NMR (400 MHz, DMSO-d 6 ) δ (ppm): 1.06 (t, 3H, CH3), 4.35 (q, 2H, CH2), 7.19–8.36 (m, 13H, aromatic H, =CH and NH2), 9.96 (s, 1H, NH). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 17.2, 65.6, 103.8, 123.7, 123.7, 124.4, 126.4, 127.4, 127.4, 127.9, 128.2, 128.2, 129.3, 129.3, 130.8, 140.1, 140.7, 149.4, 165.1, 166.7, 167. MS (EIMS) m/z: 405 (M+, 5), 236 (52), 215 (20), 103 (44), 90 (36), 89 (12), 77 (100), 64 (30), 50 (27). Anal. Calcd. for C21H19O2N5S (405): C, 62.21; H, 4.72; N, 17.27. Found: C, 62.25; H, 4.77; N, 17.31%.

Synthesis of 6-(1,3,4-oxadiazol-2-yl)-1,3-diphenyl-1H-thieno[3,2-c]pyrazol-5-amine (16). Compound 15 (0.5 gm) was heated at 120 °C for 30 min. The reaction product was purified preparative TLC on silica gel using chloroform/ethylacetate (80:20) as an eluent to give brown crystals; yield (90%). m.p. 278–280 °C. IR (KBr, cm−1) νmax = 3453, 3400 (NH2), 3063 (CH-arom) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 7.20–7.92 (m, 11H, aromatic H and CH-Oxadiazol), 11.34 (s, 2H, NH2). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 104.7, 120.3, 123.4, 123.4, 125.7, 126.2, 126.4, 126.4, 127.6, 128.1, 128.1, 128.5, 128.5, 130.8, 140.3, 140.8, 155, 165.8, 167.2. MS (EIMS) m/z: 361 (M++2, 36), 310 (28), 270 (42), 252 (35), 233 (34), 193 (34), 158 (43), 134 (32), 123 (37), 91 (36), 80 (100), 63 (46), 51 (31). Anal. Calcd. for C19H13ON5S (359): C, 63.49; H, 3.65; N, 19.49. Found: C, 63.46; H, 3.60; N, 19.43%.

Synthesis of 5-amino-N′-benzoyl-1,3-diphenyl-1H-thieno[3,2-c]pyrazole-6-carbohydrazide (18). A solution of 14 (0.01 mol) in acetonitrile (30 mL) was heated under reflux with (0.01 mol) of benzoyl chloride for 7 h. The solid which separated was collected and crystallized from ethanol to give yellow crystals; yield (61%); m.p. 100–102 °C. IR (KBr, cm−1) νmax = 3455, 3400, 3161 (NH2/NH), 3059 (CH-arom), 1747, 1662 (2CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 6.00 (s, 2H, NH2) 7.02–8.12 (m, 17H, aromatic H and 2 NH). MS (EIMS) m/z: 455 (M++2, 40), 453 (54), 423 (48), 403 (56), 364 (56), 349 (52), 297 (46), 257 (59), 237 (100), 196 (39), 183 (22), 128 (40), 62 (24). Anal. Calcd. for C25H19O2N5S (453): C, 66.21; H, 4.22; N, 15.44. Found: C, 66.25; H, 4.26; N, 15.47%.

Synthesis of N-(8-oxo-1,3-diphenyl-1H-pyrazolo [3′,4′:4,5] thieno[2,3-d]pyrimidin-7(8H)-yl) benzamide (19). A mixture of compounds 18 and (10 mL) of triethyl orthoformate were heated at reflux for 4 h. The reaction mixture was allowed to cool and poured into crushed ice. The separated solid was filtered, washed with water and crystallized from ethanol to give red crystals; yield (67%). m.p. 170–172 °C. IR (KBr, cm−1) νmax = 3448 (NH), 3060 (CH-arom), 1700, 1630 (2CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 7.21–8.00 (m, 16H, aromatic H), 9.90 (s, 1H, NH). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 105.3, 121.6, 121.6, 125.1, 126.1, 126.1, 126.2, 126.2, 127.8, 127.8, 127.8, 128.1, 128.3, 128.3, 129.4, 129.4, 130.8, 131.2, 134.1, 138.3, 140.5, 153.6, 159.3, 161.8, 165.3, 166.8. MS (EIMS) m/z: 463 (M+, 0.2), 405 (11), 320 (71), 290 (34), 274 (27), 262 (35), 246 (37), 103 (48), 91 (39), 77 (100), 57 (28), 51 (16). Anal. Calcd. for C26H17O2N5S (463): C, 67.37; H, 3.70; N, 15.11. Found: C, 67.41; H, 3.75; N, 15.16%.

Synthesis of 3-amino-5-(5-amino-1,3-diphenyl-1H-thieno[3,2-c]pyrazol-6-yl)-1H-pyrazole-4-carbonitrile (20). A mixture of 14 (0.01 mol), malononitrile (0.01 mol) in ethanol (30 mL) containing catalytic amount of piperidine was heated under reflux for 24 h. The reaction mixture was allowed to cool and poured into crushed ice then acidified with HCl. The separated solid was filtered, washed with water and crystallized from dioxane, as brawn crystals; yield (75%); m.p. 280–282 °C. IR (KBr, cm−1) νmax = 3450, 3400 (NH2/NH), 3060 (CH-arom), 2195 (CN) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 6.00 (s, 2H, NH2), 7.16–7.95 (m, 13H, aromatic H, NH and NH2). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 98, 104.8, 113.9, 120.7, 123.4, 123.4, 125.6, 126.1, 126.1, 126.2, 128.1, 128.1, 128.9, 128.9, 128.9, 129.3, 134.2, 140.1, 141.2, 153.8, 167.2. MS (EIMS) m/z: 399 (M++2, 2), 397 (3), 236 (27), 194 (6), 103 (25), 91 (42), 79 (100), 64 (69), 56 (44), 51 (31). Anal. Calcd. for C21H15N7S (397): C, 63.46; H, 3.80; N, 24.67. Found: C, 63.50; H, 3.86; N, 24.70%.

Synthesis of (5-amino-1,3-diphenyl-1H-thieno[3,2-c]pyrazol-6-yl) (3,5-dimethyl-1H-pyrazol-1-yl) methanone (21). A mixture of compound 14 (0.01 mol), and the α,β-diketone (Acetylacetone) (0.01 mol) in absolute ethanol (30 mL) was stirred under reflux for 12 h. The reaction mixture was allowed to cool to 0 °C for 24 h, The separated solid was filtered off, dried and crystallized from dioxane, as brawn crystals; yield (81%); m.p. 270–272 °C. IR (KBr, cm−1) νmax = 3439, 3400 (NH2), 3060 (CH-arom), 2921–2851 (CH-aliph), 1718 (CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 2.68 (s, 3H, CH3), 2.84 (s, 3H, CH3), 6.88 (s, 2H, NH2), 7.48–7.90 (m, 11H, aromatic H). MS (EIMS) m/z: 415 (M++2, 0.07), 413 (0.7), 365 (11), 235 (13), 219 (2), 128 (10), 105 (18), 91 (17), 77 (100), 64 (27), 51 (12). Anal. Calcd. for C23H19ON5S (413): C, 66.81; H, 4.63; N, 16.94. Found: C, 66.84; H, 4.66; N, 16.98%.

General procedure for the synthesis of thieno[3,2-c]pyrazole-6-carbohydrazide derivatives (22a–b). A mixture of compound 14 (0.01 mol), appropriate aryl aldehydes 4a–b (0.01 mol) in ethanol (30 mL) with catalytic amount of piperidine was heated under reflux for 3 h. The reaction mixture was allowed to cool and poured into crushed ice then acidified with HCl. The separated solid was filtered, washed with water and crystallized from the proper solvent to give 22a–b.

5-Amino-N′-(4-chlorobenzylidene)-1,3-diphenyl-1H-thieno[3,2-c]pyrazole-6-carbohydrazide (22a). It was obtained as pale yellow crystals from ethanol; yield (88%); m.p. 218–220 °C. IR (KBr, cm−1) νmax = 3433, 3400 (NH2/NH), 3055 (CH-arom), 1630 (CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 5.16 (s, 1H, CH-oleffinic), 7.10–8.04 (m, 17H, aromatic H, NH and NH2). MS (EIMS) m/z: 473 (M++2, 0.06), 471 (0.09), 358 (27), 247 (32), 236 (27), 103 (25), 91 (32), 77 (100), 64 (14), 51 (31). Anal. Calcd. for C25H18ON5SCl (471): C, 63.62; H, 3.84; N, 14.84. Found: C, 63.68; H, 3.89; N, 14.89%.

5-Amino-N′-(4-hydroxybenzylidene)-1,3-diphenyl-1H-thieno[3,2-c]pyrazole-6-carbohydrazide (22b). It was obtained as brawn crystals from ethanol; yield (79%); m.p. 200–202 °C. IR (KBr, cm−1) νmax = 3447 (OH), 3423, 3286 (NH2/NH), 3056 (CH-arom), 1691 (CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 5.09 (s, 1H, CH-oleffinic), 6.57–8.04 (m, 17H, aromatic H, NH and NH2), 9.00 (s, 1H, OH). MS (EIMS) m/z: 453 (M+, 0.1), 339 (1), 235 (27), 206(1), 103 (22), 91(17), 79 (100), 63 (67), 51 (6). Anal. Calcd. for C25H19O2N5S (453): C, 66.21; H, 4.22; N, 15.44. Found: C, 66.24; H, 4.26; N, 15.49%.

General procedure for the Synthesis of thieno[3,2-c]pyrazol-5-yl-acetamide derivatives (23a–b). A solution of compounds 22a–b (0.01 mol) in acetic anhydride (10 mL) was heated for 15 min. After cooling the solid that was separated was recrystallized from approper solvent to give 23a–b.

N-(6-(2-(4-chlorobenzylidene)hydrazinecarbonyl)-1,3-diphenyl-1H-thieno[3,2-c]pyrazol-5-yl) acetamide (23a). It was obtained as white crystals from benzene; yield (58%); m.p. 134–136 °C. IR (KBr, cm−1) νmax = 3440, 3400 (2NH), 3061 (CH-arom), 2950 (CH-aliph), 1681, 1616 (2CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 1.95 (s, 3H, CH3), 5.30 (s, 1H, CH-oleffinic), 7.17–8.53 (m, 15H, aromatic H and NH), 10.00 (s, 1H, NH). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 27.2, 104.9, 123.4, 123.4, 124.8, 126.3, 127.1, 127.1, 127.1, 127.2, 127.2, 128, 128.1, 128.1, 128.9, 128.9, 130.6, 131.7, 132.1, 132.1, 138.5, 141.8, 148.3, 165, 167.8, 170.2, 185.5. MS (EIMS) m/z: 516 (M++2, 1), 464 (6), 358 (15), 246 (20), 224 (9), 188 (7), 91 (27), 77 (100), 63 (28), 51 (21). Anal. Calcd. for C27H20ClN5O2S (514): C, 63.09; H, 3.92; N, 13.63. Found: C, 63.13; H, 3.92; N, 13.63%.

N-(6-(2-(4-hydroxybenzylidene)hydrazinecarbonyl)-1,3-diphenyl-1H-thieno[3,2-c]pyrazol-5-yl) acetamide (23b). It was obtained as pale yellow crystals from benzene; yield (68%); m.p. 124–126 °C. IR (KBr, cm−1) νmax = 3452, 3400, 3250 (OH, 2NH), 3060 (CH-arom), 2924 (CH-aliph), 1745, 1689 (2CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 1.96 (s, 3H, CH3), 5.25 (s, 1H, CH-oleffinic), 7.08–7.98 (m, 14 H, aromatic H), 8.58 (s, 1H, NH), 8.61 (s, 1H, NH), 10.90 (s, 1H, OH). MS (EIMS) m/z: 497 (M++2, 2), 495 (8), 451 (36), 398 (20), 353 (26), 307 (31), 244 (34), 206 (73), 167 (26), 125 (28), 93 (64), 81 (98), 70 (40), 55 (100). Anal. Calcd. for C27H21O3N5S (495): C, 65.44; H, 4.27; N, 14.13. Found: C, 65.44; H, 4.26; N, 14.13%.

Synthesis of 6-methyl-1,3-diphenyl-1,7-dihydro-8H-pyrazolo[3′,4′:4,5]thieno[2,3-d]pyrimidin-8-one (24). A solution of compound 23a–b (0.01 mol) in an ethanolic sodium ethoxide solution (prepared by dissolving 0.23 g of sodium metal in 30 mL ethanol), was heated under reflux for 12 h. The reaction mixture was evaporated under vacuum to dryness. The separated solid crystallized from benzene to give brawn crystals; yield (68%); m.p. 164–166 °C. IR (KBr, cm−1) νmax = 3442 (NH), 3061 (CH-arom), 2922 (CH-aliph), 1712 (CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 1.83 (s, 3H, CH3), 7.23–7.52 (m, 11H, aromatic H + NH). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 29.1, 105.3, 123.5, 123.5, 125.3, 126.3, 126.4, 126.4, 127.7, 128.2, 128.2, 129.0, 129.0, 130.6, 140.1, 140.1, 155.3, 156.2, 160.1, 167.2. MS (EIMS) m/z: 358 (M+, 0.1), 340 (1), 205 (2), 236 (22), 194 (2), 107 (51), 91 (32), 77 (100), 51 (27). Anal. Calcd. for C20H14N4OS (358): C, 67.02; H, 3.94; N, 15.63. Found: C, 67.13; H, 3.93; N, 15.64%.

Preparation of 7-amino-1,3-diphenyl-6-thioxo-1,5,6,7-tetrahydro-8H-pyrazolo[3′,4′:4,5] thieno[2,3-d]pyrimidin-8-one (25). To a hot ethanolic sodium hydroxide (30 mL), compound 14 (0.01 mol), and carbon disulphide (excess 5 mL) were added. The mixture was heated under reflux for 15 h. The reaction mixture was allowed to cool (0 °C), the separated solid was filtered, washed with water and crystallized from dioxane, as brawn crystals; yield (79%); m.p. 266–268 °C. IR (KBr, cm−1) νmax = 3454, 3400 (NH2/NH), 3061 (CH-arom), 1712 (CO) cm−1. 1H-NMR (300 MHz, DMSO-d 6 ) δ (ppm): 7.20–7.92 (m, 11H, aromatic H + NH), 11.31 (s, 2H, NH2). 13C-NMR (100 MHz, DMSO-d 6 ) δ (ppm): 105.3, 125.1, 125.1, 126.1, 127.1, 127.1, 127.1, 127.1, 128.3, 128.3, 128.9, 128.9, 130.6, 138.7, 140.8, 161.3, 168.1, 169.2, 185.6. MS (EIMS) m/z: 393 (M++2, 5), 391 (65), 323 (84), 279 (58), 253 (91), 200 (67), 178 (100), 112 (65), 90 (61), 51 (58). Anal. Calcd. for C19H13N5S2O (391): C, 58.29; H, 3.35; N, 17.89. Found: C, 58.32; H, 3.36; N, 17.91%.

Conclusions

The research study reports the successful synthesis and antimicrobial activity of new pyrazolone, pyrazolopyridazine, pyranopyrazole, pyrazolopyrimidine, pyrazolothiazolopyrimidinone, thiazolopyrimidine, thienopyrazole and pyrazolothienopyrimidine derivatives. The antimicrobial study revealed that all the tested compounds showed moderate to good antimicrobial and antifungal activities against pathogenic strains.

Notes

Declarations

Authors’ contributions

MAMA, SMB were responsible for the organic synthesis, and characterization experiments and department of Pharmacology, Faculty of Pharmacy, Mansoura University, Egypt for performing the antimicrobial evaluation. Both authors read and approved the final manuscript.

Acknowledgements

The authors are very grateful to Prof. Dr. I. S. Abdel Hafiz, Department of Chemistry, Faculty of Science, Arish University, Arish, Egypt, for valuable support and reviewing this manuscript and the authors are thankful to department of Pharmacology, Faculty of Pharmacy, Mansoura University, Egypt for performing the antimicrobial evaluation.

Competing interests

The authors declare that they have no competing interests.

Availability of data and materials

The authors have the samples.

Consent for publication

All authors consent to the publication.

Ethics approval and consent to participate

All authors declare that they have ethics approval and consent to participate.

Funding

Waiver.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Authors’ Affiliations

(1)
Department of Chemistry, Faculty of Science, Arish University

References

  1. Yu ZH, Shi DQ (2010) Synthesis and herbicidal activity of α-amino phosphonate derivatives containing thiazole and pyrazole moieties. Phosphorus Sulfur Silicon Relat Elem 185:1746–1752View ArticleGoogle Scholar
  2. Ranjana A, Vinod K, Rajiv K, Shiv PS (2001) Approaches towards the synthesis of 5-aminopyrazoles. Beilstein J Org Chem 7:179–197Google Scholar
  3. Tomlin CDS (2003) The pesticide manual: a world compendium, 13th edn. British Crop Protection Council, AltonGoogle Scholar
  4. Bekhit AA, Ashour HMA, Ghang YSA, Bekhit AEA, Baraka A (2008) Synthesis and biological evaluation of some thiazolyl and thiadiazolyl derivatives of 1H-pyrazole as anti-inflammatory antimicrobial agents. Eur J Med Chem 43:456–463View ArticleGoogle Scholar
  5. Frigola J, Colombo A, Pares J, Martinez L, Sagarra R, Rosert R (1989) Synthesis, structure and inhibitory effects on cyclooxygenase, lipoxygenase, thromboxane synthetase and platelet aggregation of 3-amino-4,5-dihydro-1H-pyrazole derivatives. Eur J Med Chem 24:435–445View ArticleGoogle Scholar
  6. Aziz MA, Abuorahma GEA, Hassanm AA (2009) Synthesis of novel pyrazole derivatives and evaluation of their antidepressant and anticonvulsant activities. Eur J Med Chem 44:3480–3487View ArticleGoogle Scholar
  7. Castasgnolo D, Mantti F, Radi M, Bechi B, Pagano M, Logu AD (2009) Synthesis, biological evaluation, and SAR study of novel pyrazole analogues as inhibitors of Mycobacterium tuberculosis: part 2. Synthesis of rigid pyrazolones. Bioorg Med Chem 17:5716–5721View ArticleGoogle Scholar
  8. Ahmed OM, Muhamed MA, Ahmed RR, Ahmed SA (2009) Synthesis and anti-tumor activities of some new pyridines and pyrazolo [1,5-a] pyrimidines. Eur J Med Chem 44:3519–3523View ArticleGoogle Scholar
  9. Bekhit AA, Aziemm TA (2004) Design, synthesis and biological evaluation of some pyrazole derivatives as anti-inflammatory-antimicrobial agents. Bioorg Med Chem 12:1935–1945View ArticleGoogle Scholar
  10. Bondock S, Rabie R, Etman HA, Fadda AA (2008) Synthesis and antimicrobial activity of some new heterocycles incorporating antipyrine moiety. Eur J Med Chem 43:2122–2129View ArticleGoogle Scholar
  11. Gopalakrishnan SS, Ravi TK, Manojkumar P (2009) Antioxidant and antibacterial studies of arylazopyrazoles and arylhydrazonopyrazolones containing coumarin moiety. Eur J Med Chem 44:4690–4694View ArticleGoogle Scholar
  12. Barcelo M, Ravina E, Masaguer CF, Dominguez E, Areias FM, Brea J (2007) Synthesis and binding affinity of new pyrazole and isoxazole derivatives as potential atypical antipsychotics. Bioorgan Med Chem Lett 17:4873–4877View ArticleGoogle Scholar
  13. Pospisil P, Folkers GJ (2004) Making the best account of molecular docking in drug design. Pharm Sci 29:81–92Google Scholar
  14. Cho AE, Guallar V, Berne BJ, Friesner RJ (2005) Importance of accurate charges in molecular docking: quantum mechanical/molecular mechanical (QM/MM) approach. Comput Chem 26:915–931View ArticleGoogle Scholar
  15. Ramiz MMM, Abdel Hafiz IS, Abdel Reheim MAM, Gaber HM (2012) Pyrazolones as building blocks in heterocyclic synthesis: synthesis of new pyrazolopyran, pyrazolopyridazine and pyrazole derivatives of expected antifungicidal activity. J Chin Chem Soc 59:72–80View ArticleGoogle Scholar
  16. Abdel-Reheim MAM (2016) β-Ketoesters in heterocylic synthesis: synthesis of new dihydropyridine, tetrahydropyrimidine, pyrazole, aminothiophene, pyrazolopyrimidine derivatives, and investigation of their antimicrobial activity. Int J Pharma Sci 6(3):1468–1479Google Scholar
  17. Abdel Reheim MAM, Abdel Hafiz IS, Mohamed S (2016) Utility of β-diketones in heterocyclic synthesis: synthesis of new tetrahydropyrimidinethione, pyrazole, thiophene, dihydropyridine, dihydropyrane, pyridazine derivatives and investigation of their antimicrobial activity. Eur J Chem 7(3):298–308View ArticleGoogle Scholar
  18. Pal S, Mareddy J, Devi NS (2008) High speed synthesis of pyrazolones using microwave-assisted neat reaction technology. J Braz Chem Soc 19:1207–1214View ArticleGoogle Scholar
  19. Abdel Reheim MAM, Abdel Hafiz IS, Elian MA (2016) A simple and convenient synthesis of isolated fused heterocycles based on: 6-phenyl-2-thioxo-2,3-dihydropyrimidin-4(5H)-one and 5-acetyl-6-phenyl-2-thioxo-2,3-dihydropyrimidin-4(5H)-one. Heterocycles 92(8):1397–1414View ArticleGoogle Scholar
  20. Becker W, Eller GA, Holzer W (2005) A simple synthesis of 6-phenylpyrano [2,3-c]pyrazol-4(1H)-ones. Synthesis 15:2583–2589Google Scholar
  21. Mohamed MS, Awad SM, Zohny YM, Mohamed ZM (2012) New theopyrimidine derivatives of expected antiinflammatory activity. Pharmacophore 3(1):62–75Google Scholar
  22. Abbady MS, Yoossef MSK (2014) Synthesis and biological activity of some new pyridines, pyrans, and indazoles containing pyrazolone moiety. Med Chem Res 23:3558–3568View ArticleGoogle Scholar
  23. Mohamed MS, Kamel MM, Kassem EMM, Nageh A, Nofal SM, Ahmed MF (2010) Novel 6,8- dibromo-4(3H)-quinazolinone derivatives of promising anti-inflammatory and analgesic properties. Acta Pol Pharm Drug Res 67(2):159–171Google Scholar
  24. Mohamed MS, Awad SM, Ahmed NM (2011) Synthesis and antimicrobial activities of new indolyl-pyrimidine derivatives. J Appl Pharm Sci 01(05):76–80Google Scholar
  25. Mohamed MS, Kamel MM, Kassem EMM, Abotaleb N, Nofal SM, Ahmed MF (2009) Novel 3-(p-substituted phenyl)-6-bromo-4(3H)-quinazolinone derivatives of promising anti-inflammatory and analgesic properties. Acta Pol Pharm Drug Res 66(5):487–500Google Scholar
  26. Abdel Hafiz IS, Hassanien AA, Hussein AM (1999) Alkyl heteroaromatics as building blocks in organic synthesis: the reactivity of alkyl azoles toward electrophilic reagents. Z Naturforschung B 54:923–928Google Scholar
  27. Unal D, Saripinar E, Akcamur Y (2006) A new method for the preparation of pyridazine systems: experimental data and semiempirical PM3 calculations. Turk J Chem 30:691–701Google Scholar
  28. Desai NC, Chhabaria MT, Dodiya A, Bhavsar AM, Baldaniya BB (2010) Synthesis, characterization, anticancer activity, and QSAR-studies of some new tetrahydropyrimidines. Med Chem Res 20:1331–1339View ArticleGoogle Scholar
  29. Kategaonkar AH, Sadaphal SA, Shelke KF, Shingate BB, Shigare MS (2009) Microwave assisted synthesis of pyrimido[4,5-d]pyrimidine derivatives in dry media. Ukr Bioorg Acta 1:3–7Google Scholar
  30. Gupta P, Gupta S, Sachar A, Kour D, Singh J, Sharma RL (2010) One pot synthesis of spiro pyrimidinethiones/spiro pyrimidinones, quinazolinethiones/quinazolinones, and pyrimidopyrimidines. J Heterocyclic Chem 47:324–333View ArticleGoogle Scholar
  31. Mohamed YA, Amr AE, Mohamed SF, Abdalla MM, Al-Omar MA, Shfik SH (2012) Cytotoxicity and anti-HIV evaluations of some new synthesized quinazoline and thioxopyrimidine derivatives using 4-(thiophen-2-yl)-3,4,5,6-tetrahydrobenzo[h]quinazoline-2(1H)-thione. J Chem Sci 124(3):693–702View ArticleGoogle Scholar
  32. Amr AE (2009) Synthesis and antimicrobial activities of some thiopyrimidine and thiazolopyrimidine derivatives from 1-(2-chloro-6-ethoxypyridine-4-yl)-3-(4-fluorophenyl)prop-2-en-1-one. World J Chem 4(2):201–206Google Scholar
  33. El- Sawy ER, Bassyouni FA, Abu-Bakr SH, Rady HM, Abdlla MM (2010) Synthesis and biological activity of some new 1-benzyl and 1-benzoyl-3-heterocyclic indole derivatives. Acta Pharm 60:55–71View ArticleGoogle Scholar
  34. Sawant RL, Ramdin SS, Wadekar JB (2014) Synthesis, QSAR and docking studies of 5HT2A receptor antagonizing thiazolo[3,2-a]pyrimidines as antipsychotic agents. Marmara Pharm J 18:109–119View ArticleGoogle Scholar
  35. Kamal El- Dean AM, Shaker R, Abo El-Hassan AA, Abdel Latif FF (2004) Synthesis of some thienotetrahydroquinoline derivatives. J Chin Chem Soc 51:335–345View ArticleGoogle Scholar
  36. Gewald VK, Hofmann I (1969) Notiz zur reaction von ketonen mit cyanessigsaurehydrazid und schwefel. J Prakt Chem 311:402–407View ArticleGoogle Scholar
  37. Hafez HN, El-Gazzar ABA (2008) Design and synthesis of 3-pyrazolyl-thiophene, thieno[2,3-d]pyrimidines as new bioactive and pharmacological activities. Bioorg Med Chem Lett 18:5222–5227View ArticleGoogle Scholar
  38. Daidone G, Raffa D, Plescia F, Maggio B, Roccaro A (2002) Synthesis of pyrazole-4-carbohydrazide derivatives of pharmaceutical interest. Arkivoc 11:227–235Google Scholar
  39. Abdel-Wadood FK, Abdel-Monem MI, Fahmy AM, Geies AA (2008) One-pot synthesis of 1,6-naphthyridines, pyranopyridines and thiopyranopyridines. Z Naturforschung B 63:303–312Google Scholar
  40. Murray PR, Baron EJ, Pfaller MA, Tenover FC, Yolken RH (1995) In: Wood GL, Washington JA (eds) Manual of clinical microbiology. Am Soc Microbiol, Washington, DCGoogle Scholar
  41. Jones RN, Barry AL, Gavan TL, Washington A II (1985) In: Lennette EH, Ballows A, Hausler Jr WJ, Shadomy HJ (eds) Manual of clinical microbiology, 4th edn. Am Soc Microbiol (1972), Washington, DCGoogle Scholar

Copyright

© The Author(s) 2017