Benzophenone derivs. prepn. for prodn. of UV stabilisers - by mixing alkoxybenzene with phosgene in presence of Lewis base in aromatic hydrocarbon solvent, heating with alkyl ether addn. and working up with water

摘要

Prepn. of benzophenones of formula (I) comprises reaction of an alkoxybenzene of formula (II) with phosgene in the presence of a Lewis acid in an organic solvent at 0-30 deg.C, warming the mixt. to 40-110 deg.C, and working up in aq. conditions. The solvent is an aromatic hydrocarbon; and before, during or partly after the warming step 1-20 wt.% linear or cyclic carbonate or carboxylate esters and/or 0-30 wt.% mono, di or tri-ethylene glycol- mono- or di-alkyl ether with 1-4C alkyl gp. is added. In formulae, R = independently H or 1-4C alkyl provided at least one R is H; R1 = 1-4C alkyl; and n = 1 or 2. Pref. the solvent is toluene, ethyl benzene and/or xylene, A is gamma butyrolactone and the prod. (I) is 2,2'-dihydroxy-4,4'-dimethoxy benzophenone. USE/ADVANTAGE - (I) are UV stabilisers. The process does not require halogenated solvents.