PRODUCTION OF 1-METHOXY-2-PROPYL3(7-DIETHYLAMINO-2-OX-O-2H-CHROMENE-3-YL)-3-OXOPROPIONATE

摘要

PROBLEM TO BE SOLVED: To enable to obtain the subject compound in high purity and in high yield by a technically simple method, a new method in which no catalyst is added in a transesterification of the methyl ester in an oxopropionate with methoxypropanol. SOLUTION: The objective compound expressed by formula III or a mixture of the compound of formula III with a compound of formula I is obtained by transesterifying methy13-(7-diethylamino-2-oxo-2H-chromene-3-yl)-3-oxopropionate of formula I with 1-methoxy-2-propanol of formula III without adding a catalyst. The reaction is preferably carried out at 100-120 deg.C and normal pressure, usually for 1-4 hours. Preferably, solvents or diluents are not used. Methanol generated during the reaction is not preferably removed by distillation. It is preferable to use 6-8moles of 1-methoxy-2propanol of formula II based on the compound of formula I.