Premium
A new synthetic entry to 3‐carboxamido‐4‐carboxylic acid derivatives of isoxazole and pyrazole
Author(s) -
Vicentini Chiara B.,
Mazzanti Manuela,
Morelli Carlo F.,
Manfrini Maurizio
Publication year - 2000
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570370129
Subject(s) - isoxazole , chemistry , pyrazole , hydroxylamine , hydrolysis , carboxylic acid , dicarboxylic acid , organic chemistry
Ethyl 2‐amino‐3‐methoxycarbonyl‐4‐oxo‐2‐pentenoate (3) reacts with hydroxylamine or hydrazines to give isoxazole and pyrazole ortho‐dicarboxylic acid esters 4 and 5, respectively. Partial hydrolysis of diesters 4 and 5 afforded the corresponding dicarboxylic acid monoesters 6 and 7. Amidation of the intermediate acid chlorides 8,9 followed by hydrolysis of 4‐methylesters 10, 11 gave the title compounds 1 and 2, respectively.