79852-93-0Relevant articles and documents
A New Synthesis of 3-Amino-1-aryl-2-pyrazolin-5-ones
Hyatt, John A.,Maggiulli, Cataldo A.,French, Stephen E.
, p. 773 - 774 (2007/10/02)
Reaction of ethyl 3-nitropropionate with aryldiazonium chlorides in basic medium yields ethyl 3-nitro-3-(arylhydrazono)propionates.These α-nitrohydrazones are converted by catalytic hydrogenation to 3-amino-1-aryl-2-pyrazolin-5-ones, probably via cyclization of intermediate amidrazones produced in situ.This appears to be the first route to the title compounds that does not use a substituted phenyl hydrazine intermediate and offers advantages in the preparation of pyrazolinones bearing electron-rich aryl rings.
