Reaction of 2-Methoxycarbonylamino-3,3-dichloroacrylonitrile with Phenylhydrazine in the Presence of Triethylamine

摘要

It was found previously that the reaction of 2-methoxycarbonylamino-3,3-dichloroacrylonitrile I with an excess of phenylhydrazine occurs initially through the substitution of two labile chlorine atoms by the phenylhydrazine residues followed by the intramolecular cyclization due to the addition of phenyl-hydrazine fragment to the cyano group to form 5-amino-pyrazole [1].