Synthesis and Characterization of Some Novel Thiazole, Thiazolo[3,2-A]pyridine and Thiazolo[3,2-A]-1,8-Naphthyridine Derivatives Containing Morpholine Moiety

Abstract

One pot reaction of morpholin or piperidine , ethyl cyanoactate,and thioglycollic acid afforded the novel 2-(2-morpholino-2-oxo-ethylidene)-4-thiazolidinone and 2-(2-oxo-2-(piperidin-1-yl) ethylidene) thiazolidin-4-one (1a,b).Cyclization of (1a) with chloroacetonitrile and malononitrile afforded the novel thiazolidinone derivatives (2a,b).Refluxing of (1a) with o-chlorobenzaldehyde,and chloroacetonitrile furnished (3). Compound (1a) reacted with aromatic aldehydes in refluxing ethanol affording 5arylmethylidine-4-thiazolidinone (4a,b).4-Thiazolidinone derivative (4a) was condensed with hydrazine hydrate to give (5). Thiazolo [3,2-a]pyridine and pyrano [2,3-d]thiazole derivatives (6,7) were produced through reaction of (4a,b,) with a mixture aromatic aldehyde and malononitrile. Compound (6) was reacted with ethyl isot-hiocynate and hydrazine hydrate to give the corresponding thiazolopyridine derivatives (8,9) .When compound (6) was treated with each of HCOOH, C6H5CO Cl,,and CS2 and malononitrile , the novel thiazolo [3,2-a]-1,8-naphthyridine derivatives (10-13) were obtained.