Patent ID: 7368604

Claim:
A process for preparing an aromatic acylphosphine oxide (II), wherein said process comprises converting an aromatic carboxyphosphine (I) to said aromatic acylphosphine oxide (II) according to the following rearrangement reaction: wherein R 1 is a C 6 -C 12 aryl group, which is optionally substituted by at least one aryl, alkyl, aryloxy, alkyloxy, and/or heteroatom, and wherein R 2 and R 3 each independently represent a C 1 -C 18 alkyl group, a C 2 -C 18 alkyl group optionally interrupted by one or more oxygen atoms, sulfur atoms and/or substituted or unsubstituted imino groups, a C 2 -C 18 -alkenyl group, a C 6 -C 12 -aryl group, a C 5 -C 12 -cycloalkyl group, or a C 1 -C 18 -alkoxy group, which are optionally substituted by at least one aryl, alkyl, aryloxy, alkyloxy, heteroatom, metal, —O − cation + and/or halogen.