Synthesis of 4-aminoisoxazole-3-carboxamides using base-promoted nitrosation of N-substituted cyanoacetamides
摘要:
The reactions of N-substituted cyanoacetamides with EtONO in the presence of an equimolar amount of EtONa afforded the corresponding sodium salts of hydroxyiniino derivatives in 70-95% yields. The latter were transformed into 4-amino-5-(4-bromobenzoyl)isoxazole-3-carboxamides in 30-57% yields using the known method.
Synthesis of 4-aminoisoxazole-3-carboxamides using base-promoted nitrosation of N-substituted cyanoacetamides
摘要:
The reactions of N-substituted cyanoacetamides with EtONO in the presence of an equimolar amount of EtONa afforded the corresponding sodium salts of hydroxyiniino derivatives in 70-95% yields. The latter were transformed into 4-amino-5-(4-bromobenzoyl)isoxazole-3-carboxamides in 30-57% yields using the known method.
Competitive formation of 4-aminoisoxazoles and 5-aminooxazoles in the cyclization reactions of O-alkylated hydroxyimino nitriles
作者:V. P. Kislyi、E. B. Danilova、V. V. Semenov、A. A. Yakovenko、F. M. Dolgushin
DOI:10.1007/s11172-006-0495-5
日期:2006.10
Base-catalyzed cyclization of O-alkylated α-hydroxyimino nitriles gave mixtures of 4-aminoisoxazoles and 5-aminooxazoles, their ratio depending on the substituent structures and the reaction conditions. The formation mechanism of 5-aminooxazoles in this reaction is discussed.