Patent ID: 6127581
Filing Date: 2000-10-03
Classification: C07C

Abstract:
A process for preparing fluorinated benzyl alcohols of the formula (I) ##STR4## wherein R.sup.1 is a component selected from the group consisting of C.sub.1 -C.sub.4 -fluoroalkyl groups,R.sup.2 is chlorine,R.sup.3 is a component selected from the group consisting of C.sub.1 -C.sub.8 -alkyl groups,m is an integer from 1 to 4 andn, o and p each represent, independently of one another, zero or an integer from 1 to 3,where: m+n+o+p.ltoreq.5, andwhereinA) chlorinated benzaldehydes of the formula (II) ##STR5## wherein R.sup.1, R.sup.2, R.sup.3, n and p are as defined for formula (I) andm' is zero or an integer from 1 to 3 ando' is an integer from 1 to 3,where: m'+n+o'+p.ltoreq.5,are reacted withB) alkali metal fluorides at a temperature in the range of from about 130 to 200.degree. C. in the presence of quaternary phosphonium salts in a catalytically effective amount that is less than about 2 mol %, based on chlorine atoms to be replaced, at initial concentrations of more than 2.5 mol of the chlorinated benzaldehyde of the formula (II) per kg of dipolar aprotic solvent to give fluorinated benzaldehydes of the formula (III) ##STR6## wherein the symbols R.sup.1, R.sup.2, and R.sup.3 used are as defined for formula (I), and these benzaldehydes of the formula (III) are hydrogenated with hydrogen in the presence of noble metal catalysts.