Studies with heteroaromatic amines. A new route to 2-azolylamino-2-thiazolin-4-ones

Abstract

Heteroaromatic chloroacetamides 3a–c on treatment with potassium thiocyanate afforded the thiazolylamino-thiazolines 6a–c via intermediacy of 4a–c and 5a–c. Compounds 6a–c condensed with dimethylformamide dimethylacetal (DMFDMA) to yield the Z–enamines 7a–c. The enamines 7a and 7b could be converted into the enamines 8a–e and 9a,b on treatment with amines. However, reacting 10c with morpholine afforded 11b. Compounds 9a,b, as well as 9c, were also obtained on reacting 6a–c with triethyl orthoformate and piperidine in DMF. The structures of 6a and 11b were confirmed by X-ray crystal structure determination.