| abstract |
The invention relates to a process for the preparation of m- or p-substituted phenylalkanols of the formula (I) n n n n n n n n n n in which R 1 is bonded to the phenyl ring in the m- or p-position and is C 1 -C 5 -alkyl, and R 2 , R 3 , R 4 and R 5 , independently of one another, are hydrogen or methyl, wherein an unsubstituted phenylalkanol of the formula (II) n n n n n n n n n n in which R 2 , R 3 , R 4 and R 5 have the meanings given under formula (I) is alkylated together with a C 1 -C 5 -alkyl halide of the formula (III) n R 1 -Hal (III),n n in which R 1 has the meaning given under formula (I) and Hal is halogen, in the presence of a Friedel-Crafts catalyst to give an m- or p-alkyl-substituted phenylalkanol of the formula (I), then the reaction mixture is worked-up and the desired m- or p-alkyl-substituted phenylalkanol of the formula (I) is separated off, the other formed by-products are returned to the reaction mixture and these are isomerized in the presence of a Friedel-Crafts catalyst to give the desired m- or p-alkyl-substituted phenylalkanol. From the m- or p-alkyl-substituted phenylalkanols of the formula (I), it is possible to form, by oxidation or dehydrogenation, as products of value, the corresponding aldehydes, which play an interesting role as fragrances and aroma chemicals. |