Abstract

Synthesis, Characterization and Biological Evaluation of Certain Novel Mannich Bases Containing Indole Moiety Linked with Thione Possessing Azetidine-4-one, thiazolidine-2-one and Tetrazoles

Author(s): S. Muralikrishna, Y. Padmalatha, L. K. Ravindranath and P. Raveedra Reddy

The article is aimed to synthesize, characterize and screening the biological activity of a series of N-((3-(4-chloro-3- oxo-1-((4-(4-(trifluoromethyl)phenyl)thiazol-2-yl)amino)azetidin-2-yl)-1H-indol-1-yl) methyl) piperidine-1-carboxamide. Indole-3-carbaldehyde and chloroethyl acetate were dissolved in DMF. To this reaction mixture, anhydrous K2CO3 was added and the reaction mixture was stirred at room temperature (350C) for 8 hrs to afford 2-(3-formyl-1H-indol-1-yl)acetate. To this reaction mixture, equimolar quantity of hydrazinecarbothioamide were dissolved in absolute alcohol, three drops of acetic acid was added and it was then heated on a steam bath for 5-6 hrs at 100oC to obtain ethyl2-(3-((2- carbamoylhydrazono)methyl)-1H-indol-1-yl)acetate. α-Halo ketones (chloro acetophenone, chloro acetone) 10 mM was added and the mixture was stirred at room temperature for 30 min compound to obtain ethyl 2-(3-((2-(4-(4-(trifluoromethyl) phenyl)thiazol-2-yl) hydrazono)methyl)-1H-indol-1-yl)acetate. Monocholoroacetyl chloride (0.01) was added then drop wise to Schiffs base (0.01 mol) and triethylamine (0.02 mol) in dioxane (25 mL) at room temperature to get ethyl 2-(3-(4-chloro- 3-oxo-1-((4-(4-(trifluoromethyl)phenyl)thiazol-2-yl)amino) azetidin-2-yl)-1H-indol-1-yl)acetate. After hydrolysis of this reaction mixture isobutyl, chloroformate (1:1 eq) was added and stirred for 30 min, and then aq. NaN3 (3 eq) was added and stirred for 20 min at 0oC, when 2-(3-(4-chloro-3-oxo-1-((4-(4-(trifluoromethyl)phenyl)thiazol-2-yl) amino)azetidin-2-yl)-1Hindol- 1-yl)acetyl azide was obtained. The reaction mixture is treated with Mannich bases to obtain N-((3-(4-chloro-3-oxo-1- ((4-(4-(trifluoromethyl)phenyl)thiazol-2-yl)amino)azetidin-2-yl)-1H-indol-1-yl)methyl) piperidine-1-carboxamide. The structures of these newly synthesized compounds were characterised by 1H NMR, 13C NMR, Mass, IR, and elemental analysis. The antimicriobial activity of the novel compounds was screened by agar discdiffusion method