Patent ID: 7005281

Claim:
A process for preparing organosilicon group containing photoinitiators of the formula I wherein m is a number from 1 to 200; q is 0 or 1; A is IN-C(O)—O—CHR 3 —Y— or IN-C(O)—NH—CHR 3 —Y—; A′ is A or R 1 ′; R 1 and R 1 ′, R 2 and R 2 ′ independently of one another are C 1 –C 18 alkyl or phenyl or —(O) q —SiR, R 1 ′R 2 ; R 3 is hydrogen or C 1 –C 6 alkyl, Y is a divalent group C 1 –C 10 alkylene, C 2 –C 10 alkenylene or —(CH 2 ) b —O—(CH 2 ) a —; a and b are each independently of the other a number of 1 to 6; IN is a photolabile functional moiety of the formula II or III wherein R 4 is hydrogen or —C(O)—C(O)—OH or —C(O)—C(O)—OC 1 –C 6 alkyl and n is 1–3; R 5 and R 6 are C 1 –C 12 alkyl or together are cycloC 5 –C 7 alkyl; R 7 is hydroxy, C 1 –C 6 alkoxy or morpholinyl; X is —(CH 2 ) a —, —(CH 2 ) b —O—(CH 2 ) a — or —(CH 2 ) b —O—CO—(CH 2 ) a —; a and b are each independently of the other a number of 1 to 6; which process comprises reacting a photolabile functional moiety containing a carboxy group (IN-COOH) or an alkoxycarbonyl group (IN-CO—OC 1 –C 6 alkyl) with a carbinol or amino terminated organosilicon compound of the formula IV wherein m, R 1 and R 1 ′, R 2 and R 2 ′ are as defined above and B is —Y—CHR 3 —OH or —Y—CHR 3 —NH 2 ; B′ is B or R 1 ′, in the presence of an enzyme which catalyzes the esterification, transesterification or amidation reaction.