Synthesis and Hypnotic Activity of New 4-Thiazolidinone and 2-Thioxo-4,5-imidazolidinedione Derivatives

Conveniently accessible 4-(2-(3,4-dimethoxyphenyl)ethyl-3-thiosemicarbazide (2) was converted to new 1-substituted benzylidene/furfurylidene-4- 2-(3,4-dimethoxyphenyl)ethyl-3-thiosemicarbazides (3) which furnished 2-(substituted benzylidene/furfurylidene) hydrazono-3-2-(3,4-dimethoxyphenyl)ethylthiazolidin-4-ones (4) and 1-(substituted benzylidene/furfurylidene)-amino -3-2-(3,4-dimethoxyphenyl)ethyl-2-thioxo-4,5-imidazolidinedio nes (5) on reaction with chloroacetic acid and oxalyl chloride, respectively. The structure of 5 was confirmed by X-ray diffraction studies performed on 5a. 4 and 5 were evaluated for their potentiating effects on pentobarbital induced hypnosis. Most of the compounds caused remarkable increases in pentobarbital sleeping time.