| abstract |
The present invention relates to a new process for the preparation of chlorinated diphenylmethane derivatives of formula I, wherein R is hydrogen or chloro-diphenylmethane by chlorination with chlorine gas, such that the reaction is carried out on the basis of 0.1-0 diphenylmethane; In the presence of 4 mol% α, α'-azo-bis-isobutyronitrile, at a temperature of between 70 ° C and 120 ° C, preferably between 70 ° and 80 ° C, optionally in the presence of a solvent, the unreacted diphenylmethane is optionally used. recirculated to the system in a known manner. -1- |