A series of 5-amino-1-aroylpyrazoles 3 are synthesized directly by the reaction of beta-aminocrotononitrile 1 with some structures containing the hydrazine moiety (X-NHNH2) 2 by refluxing ethanol in presence of sodium acetate. When semicarbazide 3i was used (X = CONH2), the reaction afforded the unexpected 7-aminopyrazolo[1,5-a]pyrimidine 4. (C) 2008 Elsevier Ltd. All rights reserved.