Synthesis of thiazolyltriazole substituted azetidinones as antimicrobial agents

321-325The reaction of ethyl 2-amino-4-methylthiazole-5-carboxylate 1 with acetic anhydride followed by reaction with hydrazine hydrate yields the ethyl 2-acetamido-4-methylthiazole-5-carboxylate 2 and N-[5-(hydrazinecarbonyl)-4-methylthiazol-2-yl]acetamide 3, respectively. The compound 3 on further reaction with alcoholic potassium hydroxide-carbon disulphide followed by cyclization with hydrazine hydrate gives N-[5-(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)-4-methylthiazol-2-yl]acetamide 5. The compound 5 is then condensed with different aromatic aldehydes to offer Schiff bases 6a-h. The Schiff bases on cyclization with chloroacetyl chloride in presence of triethylamine as catalyst furnish the azetidin-2-one 7a-h. The compounds are synthesized in good yield and the chemical structures of the compounds are elucidated from their IR, 1H NMR, and elemental analysis. All the synthesized compounds have been screened for their antimicrobial activity

Synthesis and Antimicrobial Activity of SomeNovel Benzimidazolyl Chalcones

Some novel benzimidazolyl chalcones were synthesized by condensation of N-(4-(1H-benzo[d]imidazol-2-yl)phenyl)acetamide with aromatic aldehydes in presence of aqueous potassium hydroxide solution at room temperature. All the synthesized compounds were characterized on the basis of their IR, 1H NMR spectroscopic data and elemental analysis. All the compounds have been screened for antimicrobial activity by the cup-plate method

The Behavior of (cyclic-alkylidene)hydrazinecarbothioamides in Cyclization with Dimethyl acetylenedicarboxylate

A series of (Z)-methyl 2(Z)-3-substituted-2-(cycloalkylidenehydrazono)-4-oxothiazolidin-5-ylidene)-acetate derivatives were synthesized via condensation alkylidene-N-substituted hydrazinecarbothioamides with dimethyl acetylenedicarboxylate. The synthesized compounds were characterized by using different spectroscopic methods and confirmed by single crystal X-ray analysis. The behavior of (cyclic-alkylidene) hydrazinecarbothioamides in cyclization was presented. The mechanism of transformation of (Z)-methyl 2-((Z)-3-(cyclopentylideneamino)-4-oxo-2-(phenylimino)thiazolidin-5-ylidene)acetate (14) into the more stable (Z)-Methyl 2-[(Z)-2-(cyclopentylidenehydrazono)-4-oxo-3-phenylthiazolidin-5-ylidene]acetate (5a) was discussed and confirmed