REACTION OF SCHIFF BASES WITH THIOGLYCOLIC ACID: SYNTHESIS OF THIAZEPINE-1(2H)-ONE AND THIAZOLIDINE-4-ONE COMPOUNDS

Abstract

Reaction of Schiff bases with thioglycolic acid was set up with Dean stark apparatus in toluene. The Schiff bases containing aniline derivatives 1a and 2a gave thiazolidin-4-one containing compounds 1b and 2b only; 1-naphthyl amine gave a mixture of thiazolidin-4-one (3b) and thiazepin-1(2H)-one (3b’) containing compounds; 2-naphthyl amine (4a) gave and thiazepin-1(2H)-one containing compound 4b. The yields of reaction were moderate to high. The structures of these compounds were elucidated by ¹H and ¹³C NMR and mass spectral analysis. Biological test results showed that Schiff base 4a was not active on any bacteria. Thiazolidine-4-one compound 1b was not active on bacteria and fungi, but was active against KB with IC₅₀ 21.33 (mg/mL). Thiazepine compound 4b exhibited activity on Staphyloccccus aureus bacterium at IC₅₀ 64.00 (mg/mL) and cancer cell line KB at IC₅₀ 11.52 (mg/mL).