A Simple Synthesis of 1-Substituted 5-Aminopyrazoles and Pyrazolo[1,5-a]-s-triazine Derivative
摘要:
Dialkyl 5-amino-1-carbamoylpyrazole-3,4-dicarboxylates (3) and the l-aryl derivatives (5) are synthesized directly by the reaction of semicarbazide (2) or arylhydrazines (4) with dialkyl (E)-2,3-dicyanobutendioates (1) in the presence of organic salts, such as ammonium acetate or sodium acetate. Furthermore, the reaction of the 1,3-diamino compound (3; R= Et) with trimethyl orthoformate in acetic acid led to the formation of diethyl 7-hydroxypyrazolo[1,5-a]-s-triazine-2,3-dicarboxylate (6).