The present invention relates to a novel process for the preparation of 1-alkyl or 1-cycloalkyl derivatives of 3-hydroxy-4-oxo-1,4-dihydropyridine-2-carboxamide of formula I.
The process includes reacting an amine R
2
NH
2
with a compound of formula II in a solution of metal hydroxide in water to give a compound of formula III. Subsequent reaction of the compound of formula III with an acid chloride formation reagent in an inert solvent gives compounds of formula I. The acid chloride formation reagent is selected from oxalyl chloride and dimethylformamide, dimethylchloromethylene-ammonium chloride and thionyl chloride and dimethylformamide. If desired, a compound of formula I where R
5
is hydrogen may be formed when an intermediate substituent is used wherein R
5
is an alcohol protective group removable by catalytic hydrogenation.
本发明涉及一种新型方法,用于制备式I的1-烷基或1-环烷基的3-羟基-4-氧代-1,4-
二氢吡啶-2-羧酰胺衍
生物。该方法包括将胺R2NH2与式II的化合物在
水中的
金属氢氧化物溶液中反应,以得到式III的化合物。随后,在惰性溶剂中使用酸
氯化物形成试剂与式III的化合物反应,得到式I的化合物。酸
氯化物形成试剂选自
草酰氯和二甲基甲酰胺、二
甲基氯甲基胺盐酸盐和亚
磺酰氯和二甲基甲酰胺。如果需要,当使用中间体取代基时,可以形成式I的化合物,其中R5为氢,R5是通过催化氢化可去除的醇保护基。