Ureas with heterocyclic substituents

Ureas with heterocyclic substituents are prepared by the reaction of heterocyclic amines with aryl or alkyl isocyanates. The pyridyl ureas possess excellent anti-inflammatory properties and the 3-ureido-pyrrolidines have novel pharmacological properties (analgesic, central nervous system, and psychopharmacologic activities). 

Condensation reactions can be grouped into two categories. The first category involves pyrazol-3-ones with formyl, acyl, nitroso, a,jS-unsaturated oxo, 3-oxo-2-azobutyric acid ethyl ester or acetonitrile substituents at position 4 or formyl substituents at position 5 and their reaction with carbanions, heterocyclic methylcarbenium salts, primary and secondary amines, diamines, heterocyclic perchlorates, hydroxylamine, hydrazines, urea or thiosemicarbazide. The second category involves pyrazol-3-ones with amino, hydrazino, heteroaromatic amino, acetyl or acetonitiilo groups at position 4 and their reaction with aryl or heteroaromatic aldehydes or cyclic ketones. 

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