Patent ID: 6924389

Claim:
A process for preparing diphosphines of formula I R 1 R 2 P—H 2 C—Ar—CH 2 PR 1 R 2 (I) which comprises: a) reacting a dim ethyl compound of formula II H 3 C—Ar—CH 3 (II) with a base and an N-substituted aminophosphorus halide to form a bis(aminophosphinomethyl) compound of formula III R 3 R 4 P—H 2 C—Ar—CH 2 —PR 3 R 4 (III) b) reacting the compound of formula III with HCl to form a bis(dichlorophosphinomethyl) compound of formula IV Cl 2 P—H 2 C—Ar—CH 2 —PCl 2 (IV) and c) reacting the compound of formula IV with an organometallic reagent to give the product compound of formula I, wherein groups R 1 and R 2 are each, independently of one another, are: (i) heteroaromatics having a five-, six- or seven-membered ring and nitrogen, oxygen or sulfur atoms in the ring, where further aromatic, heteroaromatic and/or aliphatic rings are optionally fused onto the ring and the rings optionally bear up to seven substituents selected from the group consisting of (C 1 -C 8 )-alkyl, O-alkyl-(C 1 -C 8 ), O-phenyl, phenyl, fluorine, chlorine, CN, COOH, CHO, SO 3 H, SO 3 alkyl-(C 1 -C 6 ), SO-alkyl-(C 1 -C 8 ), CF 3 , COO-alkyl-(C 1 -C 8 ), COO-phenyl, PO-phenyl 2 , PO-alkyl 2 -(C 1 -C 4 ), PO 3 H 2 , PO—(O-alkyl-(C 1 -C 6 )) 2 , SO 3 -alkyl-(C 1 -C 4 ); (ii) cyclic or acyclic alkyl radicals which contain up to 10 carbon atoms and optionally bear up to seven substituents selected from the group consisting of (C 1 -C 8 )-alkyl, O-alkyl-(C 1 -C 8 ), O-phenyl, phenyl, fluorine, chlorine, CN, COOH, CHO, SO 3 H, SO 2 -alkyl-(C 1 -C 6 ), SO-alkyl-(C 1 -C 6 ), CF 3 , COO-alkyl-(C 1 -C 8 ), COO-phenyl, PO-phenyl 2 , PO-alkyl 2 -(C 1 -C 4 ), PO 3 H 2 , PO—(O-alkyl-(C 1 -C 8 )) 2 and SO 3 -alkyl-(C 1 -C 4 ); or (iii) aromatics having up to 14 carbon atoms and are able to bear up to eight substituents selected from the group consisting of (C 1 -C 8 )-alkyl, O-alkyl-(C 1 -C 8 ), O-phenyl, phenyl, fluorine, chlorine, CN, COOH, CHO, SO 3 H, SO 2 -alkyl-(C 1 -C 6 ), SO-alkyl-(C 1 -C 8 ), CF 3 , COO-alkyl-(C 1 -C 8 ), COO-phenyl, PO-phenyl 2 , PO-alkyl 2 -(C 1 -C 4 ), PO 3 H 2 , PO—(O-alkyl-(C 1 -C 6 )) 2 and SO 3 -alkyl-(C 1 -C 4 ), wherein, when the aromatic group is a substituted phenyl group, the phenyl group can not be substituted by fluorine, trifluoromethyl or C 1-8 -alkyl; and Ar is a substituted or unsubstituted aromatic or heteroaromatic hydrocarbon group and R 3 and R 4 are each, independently of one another, an N-substituted alkylamino or arylamino group.