反应详情

Compound (250) can be prepared in the same manner as in Preparation Example 240, except for replacing compound (P102) with 4-chloro-3,5-difluorophenol. The 4-chloro-3,5-difluorophenol can be prepared by reacting a Grignard reagent prepared from 1-bromo-4-chloro-3,5-difluorobenzene with t-butyl hydroperoxide or converting the same Grignard reagent to a boric ester, and oxidizing the product with hydrogen peroxide under a basic condition. It is also prepared by nitrating 2-chloro-1,3-difluorobenzene (obtainable by decomposing a diazonium salt of 2,6-difluoroaniline in the presence of cuprous chloride or in hydrochloric acid), reducing the nitro-compound to obtain 4-chloro-3,5-difluoroaniline, and decomposing its diazonium salt in sulfuric acid.