Environmentally Friendly Heterocyclic Systems from Simple Acyclic Compounds

Abstract

The current work illustrates the versatile role of 5- cyanomethyl thiadiazole and 2-aminothiadiazole derivatives in the synthesis of different heterocyclic systems from simple readily obtainable materials. The work can be divided into three main parts:- i- Synthesis of 5-cyanomethylthiadiazol and its reactions. ii- Synthetic utility and chemical behaviour of 2-aminothiadiazole derivative. iii- Study of insecticidal activity of the synthesized compounds. First part: Synthesis of 5-cyanomethyl thiadiazole and its reactions:- 2-Chloro-N-(5-(cyanomethyl)-1,3,4-thiadiazol-2-yl)benzamide (5) has been synthesized via reaction of 2-chlorobenzoyl chloride 1 with ammonium thiocyanate in dry acetonitrile to afford the 2-chlorobenzoyl isothiocyanate 2, to which cyanoacetohydrazide 3 was added in situ with stirring, then refluxing the produced 2-chloro-N-(2-(2-cyanoacetyl)hydrazine-1-carbonothioyl)benzamide (4) in glacial acetic acid. Heterocyclization of 5 with thioglycolic acid in dry pyridine afforded the thiazolidinone derivative 6, which reacted with p-nitrobenzaldehyde in presence of anhydrous sodium acetate as a catalyst in glacial acetic acid to afford the product 7 [cf. scheme I].