Process for the preparation of acylphosphines, acyl oxides and acyl sulfides

A process for the preparation of acylphosphine oxides and acylphosphine sulfides of formula IV

• wherein
• n is 1 or 2;
• when n is 1, m is 1;
• when n is 2, m is 1 or 2;
• R1, when n=1, is
• C1–C18alkyl, C2–C18alkyl which is interrupted by one or several non-successive O atoms;
• phenyl-substituted C1–C4alkyl, C2–C8alkenyl, phenyl, naphthyl, biphenyl, C5–C12cycloalkyl or a 5- or 6-membered O-, S- or N-containing heterocyclic ring, the radicals phenyl, naphthyl, biphenyl, C5–C12cycloalkyl or the 5- or 6-membered O-, S- or N-containing heterocyclic ring being unsubstituted or substituted by one to five halogen, C1–C6alkyl, C1–C8alkylthio and/or C1–C8alkoxy;
• R1, when n=2, is
• C1–C18alkylene, C2–C18alkylene which is interrupted by one or several non-successive O atoms;
• or
• R1 is C1–C6alkylene which is substituted by C1–C4alkoxy, phenyl, C1–C4alkylphenyl, phenyl-C1–C4alkyl or C1–C4alkoxyphenyl;
• or R1 is phenylene or xylylene, which radicals are unsubstituted or substituted by one to three C1–C4alkyl and/or C1–C4alkoxy, or R1 is a —CH2CH═CHCH2—,
• R2 is C1–C18alkyl, C3–C12cycloalkyl, C2–C18alkenyl, phenyl, naphthyl, biphenyl or a 5- or 6-membered O-, S- or N-containing heterocyclic ring, the radicals phenyl, naphthyl, biphenyl or 5- or 6-membered O-, S- or N-containing heterocyclic ring being unsubstituted or substituted by one to four C1–C8alkyl, C1–C8alkoxy, C1–C8alkylthio and/or halogen;
• R3 is C1–C18alkyl, C2–C18alkyl which is interrupted by one or several non-successive O atoms;
• phenyl-substituted C1–C4alkyl, C2–C8alkenyl, phenyl, naphthyl, biphenyl, C5–C12cycloalkyl or a 5- or 6-membered O-, S- or N-containing heterocyclic ring, the radicals phenyl, naphthyl, biphenyl, C5–C12cycloalkyl or the 5- or 6-membered O-, S- or N-containing heterocyclic ring being unsubstituted or substituted by one to five halogen, C1–C8alkyl, C1–C8alkylthio and/or C1–C8alkoxy;
• Q is a single bond, CR6R7, —O— or —S—;
• R4 and R5 are each independently of the other hydrogen, C1–C4alkyl or C1–C4alkoxy;
• R6 and R7 are each independently of the other hydrogen or C1–C4alkyl;
• and
• Z is O or S,
• by
• (1) reacting organic phosphorus halides of formula II
• wherein Y is Br or Cl and
• R1, R3, n and m have the meaning cited above,
• with an alkali metal or with magnesium in combination with lithium, or with mixtures thereof,
• optionally in the presence of a catalyst, and
• (2) subsequent reaction with m equivalents of acid halides of formula III
• wherein R2, m and Y have the meaning above, and
• (3) oxidation or reaction with sulfur of the acylphosphine of formula I
• which is obtained by reaction (2),
• wherein R1, R2, R3, m and n have the meaning cited above,
• which process is carried out without isolation of the intermediates.