Process for the preparation of benzonorbornenes

摘要

The present invention relates to a novel a process for the preparation of 2,9-dichloromethylidene-5-amino-benzonorbornene which process comprises
a) reacting cyclopentadiene in the presence of a radical initiator and CXCl 3 , wherein X is chloro or bromo, to a compound of formula II
b) reacting the compound of formula II with a base in the presence of an appropriate solvent to the compound of formula III
c) and converting the compound of formula II in the presence of 1,2-dehydro-6-nitrobenzene to the compound of formula IV
and d) hydrogenating the compound of formula IV in the presence of a metal catalyst.