PRODUCTION OF 5-PERFLUROALKYLDIHYDROURACIL DERIVATIVE

摘要

PROBLEM TO BE SOLVED: To obtain the subject derivative having industrial safety and useful e.g. as an intermediate for pharmaceuticals such as carcinostatic agent under controlled heat-generation in high yield by reacting a specific acrylic acid with a urea derivative in the presence of acetic anhydride. SOLUTION: The objective 5-perfluoroalkyldihydrouracil derivative expressed by formula III (e.g. 5-trifluoromethyldihydrouracil) can be produced by reacting (A) an α-perfluoroalkylacrylic acid expressed by formula I (Rf is a 1-10C α- perfluoroalkyl) (e.g. α-trifluoromethylacrylic acid) with (B) a urea derivative expressed by formula II (R<1> and R<2> are each H, methyl or ethyl) (e.g. methylurea) preferably at 70-120 deg.C while removing the produced acetic acid from the reaction system. Preferably, the molar ratio of A/B is 1.5-4.0 and the amount of acetic anhydride is 3-10 pts. based on 1 pt. of the total addition amount of the component A.