A facile synthesis of pyrazole, isoxazole and pyrimidine ortho-dicarboxylic acid derivatives via β-enaminoketoesters
作者:Augusto C. Veronese、Rosella Callegari、Carlo F. Morelli、Chiara B. Vicentini
DOI:10.1016/s0040-4020(97)00940-x
日期:1997.10
β-Alkoxycarbonyl-β-enaminoketoesters 1a,b react with hydrazines to give pyrazole ortho-dicarboxylic acid derivatives 3, 4 and 5. Similarly 1a reacts with hydroxylamine to give isoxazole 6 and with amidines and guanidine to give pyrimidine ortho-dicarboxylic acid monoesters 7a-c. The total or partial hydrolysis of selected heterocycles afforded the dicarboxylic acids 8, 9 and 10 and the dicarboxylic
A new synthetic entry to 3-carboxamido-4-carboxylic acid derivatives of isoxazole and pyrazole
作者:Chiara B. Vicentini、Manuela Mazzanti、Carlo F. Morelli、Maurizio Manfrini
DOI:10.1002/jhet.5570370129
日期:2000.1
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