Reactions with 2-Thiohydantoin, Synthesis of Imidazothiazolone Derivatives and Mannich Bases of 5-Arylidene-2-thiohydantoin

Abstract

Treatment of 5-arylidene-2-thiohydantoin (1a-d) with alkyl bromoacetate and chloroacetic acid gave the esters 2a-f and the acids 2g-j, respectively. 2a was refluxed with concentrated hydrochloric acid to give 5-benzylidene hydantoin. 2 was cyclized with acetic anhydride to give the bicyclic product 3. 5-Arylidene-2-thiohydantoin derivatives (1a, b) and (8a) condense with formaldehyde and primary or secondary amines to give the corresponding Mannich bases 6a-f and 8c-e, respectively. The assigned structure 6 and 8 finds support from the chemical evidences