Moged A. Berghot

Synthesis and antimicrobial activities of some new thiazole and pyrazole derivatives based on 4,5,6,7-tetrahydrobenzothiophene moiety.

2-(5-oxothiazolidinone)-cyanoacetamido derivative 3 was prepared in two steps by reaction of 2-(2-cyano-acetylamino)-4,5,6,7-tetrahydro-benzo[b]thiophene-3-carboxamide (1) with phenyl isothiocyanate and chloroacetyl chloride, which diazocoupled with p-tolyldiazonium chloride in pyridine to afford the corresponding hydrazono derivative 4. Also, condensation of 3 with p-anisaldehyde gave the corresponding arylidine derivative 5. Treatment of 2 with dimethyl sulfate afforded the ketene N,S-acetal 9 which give 5-amino pyrazole derivative 10 upon treatment with hydrazine hydrate. Compound 10 was used as key intermediate for synthesis of pyrazolo[5,1-c][1,2,4]triazine 13a, b, pyrazolo[5,1-a]pyrimidine 14-17 and pyrolo pyrazole 18 derivatives. Finally, condensation of 1 with DMF-DMA afforded the corresponding acryloamide derivative 19, which afforded the corresponding pyrazole derivative 20 upon heating with hydrazine hydrate. All new synthesized compounds were evaluated as antimicrobial agents; some of them exhibited promising activities.

Synthesis and antibacterial activity of some new thiazole and thiophene derivatives

Dibenzobarrelene 1 was reacted with cyanoacetic acid hydrazide and thiosemicarbazide to give the corresponding 3-oxo-propiononitrile and thioamide derivatives 2 and 16, respectively. The base-catalyzed reaction 3-oxo-propiononitrile derivative 2 with phenyl isothiocyanate yielded the non-isolable intermediate 3. Treatment of 3 with dilute HCl afforded the corresponding thiocarbamoyl derivative 4. The intermediate 3, thiocarbamoyl 4 and thioamide derivatives 16 were utilized as key intermediates for the synthesis of some new thiazole 5, 6a, 6b, 7, 8, 10a, 10b, 12, 14a, 15, 17a, 17b, and 18; and thiophene 13a-d derivatives, respectively. The newly synthesized compounds were characterized by IR, (1)H NMR, (13)C NMR and mass spectral studies. Representative compounds of the synthesized product were tested and evaluated as antibacterial agent.

Convergent synthesis and antibacterial activity of pyrazole and pyrazoline derivatives of diazepam.

Polysubstituted pyrazoles (5)(a-l), pyrazolines (7)(a-c), (8)(a-c) and pyrazolotriazine (10) derivatives of diazepam were synthesized. The structures of hitherto unknown compounds were established by analytical and spectral methods. Some of these compounds were screened to test their antibacterial activity against gram-positive (B. subtilis) and gram-negative (P. aeruginosa). All compounds showed potent activity against these bacteria.

Synthesis, antitumor and antioxidant evaluation of some new thiazole and thiophene derivatives incorporated coumarin moiety

Abstract3-Acetylcoumarin (1) was utilized as a key intermediate for the synthesis of 2-aminothiazole derivative 3via bromination of 1 followed by treatment of the formed acetylbromide 2 with thiourea or via Bignailli reaction of 1. Treatment of 3 with 2 afforded the bis-coumarin 4, whereas, cyanoacetylation of 3 followed by treatment of the formed cyanoacetamide 6 with salicyaldehyde give the bis-coumarin 7. Reaction of 6 with phenyl isothiocyanate in DMF/KOH produced the potassium salt 8, which cyclized with chloroacetyl chloride to give the thiazolidinone 9. Acidification of 8 with HCl afforded the thiocarbamoyl 10, which condensed with 2 in DMF to give the mercapto derivative 12, whereas in DMF/TEA gave the thiophene derivative 13. The thiophenes 15a–c were achieved via treatment of the thiocarbamoyls 14a–c with 2 in DMF/TEA, whereas, in DMF gave the corresponding thiazoles 16a–c. Treatment of the components 17a, b with carbon disulfide in DMF/KOH followed by addition of 2 afforded the dithioacetals 19a, b. Cyclization of 19b under alkaline condition gave the desired thiophene 20. Representative compounds of the synthesized products were evaluated as antitumor and antioxidant agents.Graphical Abstract3-Acetylcoumarin (1) was utilized as a key intermediate for the synthesis of different coumarin derivatives. Newly synthesized compounds were elucidated by analytical and spectral data. Representative compounds of the synthesized products were evaluated as antitumor and antioxidant agents.

Synthesis and antibacterial activity of some new heterocycles incorporating phthalazine

3-(1,4-Dioxo-3,4,4e,5,10,10a-hexahydro-1H-5,10-benzeno-benzo[g]phthalazin-2-yl)-3-oxo-propiononitrile (1) was utilized as key intermediate for the synthesis of some new iminocoumarin 2, chromenone 3, aminothiazole 4, triazepine 5a, b and 6, hydrazono-propiononitrile 7, pyridopyrazotriazine 8, monobromo 9, dibromo 10 quinoxaline 11, ketene N,S-acetal 13, ketene S,S-diacetal 17 and 18a, b and methyl dithioate 20 derivatives, respectively. The newly synthesized compounds were characterized by IR, (1)H NMR, (13)C NMR and mass spectral studies. Representative compounds of the synthesized product were tested and evaluated as antibacterial agent.

Synthesis and antimicrobial of new anthraquinone derivatives incorporating pyrazole moiety.

Treatment of 2-cyano-N-(9,10-dioxo-9,10-dihydro-anthracen-2-yl)-acetamide (1) with phenyl isothiocyanate/dimethylsulphate afforded the corresponding ketene N,S-acetal 2 which upon treatment with hydrazine hydrate and 4-aminoantipyrine afforded the pyrazolo derivatives 3 and 4, respectively. 3-aminopyrazole derivative 3 was utilized as key intermediate for the synthesis of pyrazolo[3,4-d]pyrimidine 5, pentaaza-as-indacene 6, triaza-cyclopenta[c]phenanthrene 7, pyrazolo[1,5-a]pyrimidine 8, 9 and (dimethyl-pyrrol-1-yl)pyrazole 10 derivatives. Furthermore, treatment of 1 with DMF/DMA gave the corresponding acrylamide derivative 11 which upon treatment with hydrazine hydrate afforded the corresponding 3-aminopyrazole derivative 12. Moreover, coupling of 1 with 4,6-dimethyl-1H-pyrazolo[3,4-b]pyridin-3-diazonium chloride gave the hydrazone derivative 13 which upon cyclization with acetic acid afforded the corresponding pentaaza-fluorene derivative 14. Representative compounds of the synthesized products were evaluated as antimicrobial agents. Some of these compounds exhibited promising activities.

Synthesis and Antioxidant and Antitumor Activity of Novel Pyridine, Chromene, Thiophene and Thiazole Derivatives

2‐Tosylacetonitrile (1) when reacted with α,β‐unsaturated nitriles 2a–c or a mixture of formaldehyde and 3‐amino‐2‐substituted‐pent‐2‐endinitriles 6a,b yielded pyridine derivatives 3a–c and 9a,b, respectively, while when subjected to react with salicylaldehyde yielded chromene derivatives 4 and 5, subsequently. The behavior of thiocarbamoyl derivative 10 derived from 1 towards some α‐halogenated compounds have been investigated as well as its behavior towards elemental sulfur and phenyl isothiocyanate. Newly synthesized compounds were screened for their antioxidant activity, erythrocytes haemolysis and bleomycin‐independent DNA damage. Some of the tested compounds exhibited promising activities.

Synthesis and study of some new 1,3-isoindoledione derivatives as potential antibacterial agents.

In an effort to establish new candidates with improved antibacterial activities, we reported here the synthesis and in vitro antibacterial evaluation of various series of 2-substituted-3a,4,9,9a-tetrahydro-4,9-benzeno-benz[f]isoindole-1,3-diones: 4-acetyl-phenyl 2, 2,2-dibromoacetylphenyl 3, benzimidazole 4, acetylbenzimidazole 5, aminophenyl 6, acetamide 7, naphthalene 8, disulfide 9, mercaptophenyl 10, hydroxyphenyl 11, phenyl ester 12, triazole 13, benzothiophene 14, benzothiazole 15 phenylazo 16a, b and aminomethane 17 derivatives. The newly synthesized compounds were characterized by (IR, (1)H NMR, (13)C NMR and mass spectrum studies). Representative compounds of the synthesized products were established and evaluated as antibacterial agents.

Synthesis and Antimicrobial Evaluation of Some New Thiophene Derivatives

2-(2-Cyano-acetylamino)-4,5,6,7-tetrahydro-benzo[b]thiophene-3-carboxamide(3) was used as starting material for synthesis of 4-thiazolidinone, thiazolidine, and thiophene derivatives 6, 7a, b, and 8a, b, respectively. Thiocarbomyl derivative 5, 4-thizolidinone 9, and thioxothiazolidine 10 were obtained from reaction of 3 with thioglycolic acid and phenyl isothiocyanate/sulfur, respectively. Condensation of 3 with selected cyclic ketones and aromatic aldehydes yielded the arylidine derivatives 11a, b and 13, respectively. Refluxing of 11a, b with sulfur and morpholine yielded the thiophene derivatives 12a, b, respectively. Diazocoupling of compound 3 withp-tolyl diazonium chloride yielded the hydrazone derivative 14. The newly synthesized compounds were characterized by infrared, 1H NMR, and mass spectral studies. Representative compounds of the synthesized product were tested and evaluated as antimicrobial agents. Compound 12b gives very high antimicrobial activity against Ampicillin.

Chemistry of 2-Amino-3-cyanopyridines

Abstract This review presents a systematic and comprehensive survey of the method of preparation and the chemical reactivity of 2-amino-3-cyanopyridines. The target compounds are important intermediates for the synthesis of a variety of synthetically useful and novel heterocyclic systems. GRAPHICAL ABSTRACT