Patent ID: 7196228

Claim:
Process for the preparation of dimer or multimer forms of BAPO compounds of the formula I, wherein R 1 is unsubstituted or substituted C 1 –C 12 alkyl, benzyl, C 1 –C 12 alkoxy or C 3 –C 8 cycloalkyl; R 2 is unsubstituted or substituted C 3 –C 6 cycloalkyl or C 5 –C 14 aryl; Q is a di- tri or tetravalent arylene residue; n is 1–4, m is 0–2, n+m is 2, 3 or 4, characterized in that (n+m) equivalents of a dimetalated-phosphine R 1 P(M) 2 are reacted with one equivalent of a di- or polycarboxylic acid halogenide to form an intermediate of the formula III the intermediate III is then reacted with (n+m) equivalents of a further carboxylic acid halogenide (R 2 —CO-Hal) to form dimer or multimer forms of bisacylphosphine-intermediates of the formula IV said phosphines IV are then oxidized to form phosphine oxides of the formula I, wherein M is Li, Na or K.