Patent ID: 7087787

Claim:
A process for the preparation of compounds of the formula (I): in which: Ar is an optionally substituted aromatic ring system having 4 to 20 carbon atoms, X is a leaving group, R 3 is unbranched alkyl having 1 to 20 carbon atoms, branched alkyl having 3 to 20 carbon atoms, cyclic alkyl, C 1 –C 4 -alkyl-substituted cyclic alkyl, phenyl, or benzyl, which is optionally substituted or unsubstituted, and optionally contains at least one heteroatom, and p denotes para with respect to the two methylene radicals on both sides of Ar, the process comprising the following steps: a) reacting a compound of the formula (II): p-X—CH 2 —Ar—CH 2 —X (II) in which Ar and X are as defined under the formula (I), with an organic sulfide of the formula (III): R 4 —S—R 5 (III) in which: R 4 and R 5 are identical or different and are unbranched alkyl having 1 to 20 carbon atoms, branched alkyl having 3 to 20 carbon atoms, cyclic alkyl having 3 to 10 carbon atoms, or C 1 –C 4 -alkyl-substituted cyclic alkyl, or R 4 and R 5 together form a ring, which optionally contains at least one heteroatom selected from the group consisting of oxygen, sulfur, and nitrogen, to give a compound of the formula (IV): in which R 4 , R 5 , X, and Ar are as defined above, b) reacting the compound of the formula (IV) with from 0.85 to 1.1 equivalents of a mercaptan of the formula (V): R 3 —SH (V) in which: R 3 is unbranched alkyl having 1 to 20 carbon atoms, branched alkyl having 3 to 20 carbon atoms, cyclic alkyl, C 1 –C 4 -alkyl-substituted cyclic alkyl, phenyl, or benzyl, which optionally is substituted or unsubstituted and optionally contains at least one heteroatom, to give a compound of the formula (VI): c) warming of the compound of the formula (VI) in a liquid and formation of the compound of the formula (VII): p-X—CH 2 —Ar—CH 2 —S—R 3 (VII) by elimination of the organic sulfide of the formula (III), where the compound of the formula (VII) is dissolved in the above liquid, d) oxidizing the compound of the formula (VII) with an oxidant, to give the compound of the formula (I).