摘要

A practical process has been developed for scalable preparation of 4-aminophenylboronic acid pinacol ester through facile two-step procedure. After boron trifluoride etherate efficiently activated the reaction of 4-bromoaniline with diphenyl ketone, metalation reaction of protected 4-bromoaniline with lithium trialkylmagnesiate readily proceeded under mild conditions (-20 degrees C), which was subsequently subjected to esterification and deprotection reaction to give the 4-aminophenylboronic acid pinacol ester. The improved synthetic route has been successfully scaled up to kilogram quantities in good yield and high quality.