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
2-氨基-3-甲氧基羰基-4-氧代-2-戊烯酸乙酯(3)与羟胺或肼反应,分别得到异恶唑和吡唑原二羧酸酯4和5。二酯4和5的部分水解得到相应的二羧酸单酯6和7。中间体酰氯8,9的酰胺化,随后4-甲基酯10、11的水解分别得到标题化合物1和2。