Patent ID: 6245944
Filing Date: 2001-06-12
Classification: C07C

Abstract:
A regioselective process for preparing a compound of the formula I ##STR9##where R.sup.1 and R.sup.2 are hydrogen or C.sub.1 -C.sub.4 -alkyl and R.sup.3 is C.sub.1 -C.sub.10 -alkyl, phenyl or C.sub.1 -C.sub.4 -alkyl-substituted phenyl, which comprises reacting a compound II ##STR10##with a compound of the formula III ##STR11##where X is chlorine, bromine or iodine, in the presence of a Friedel-Crafts catalyst selected from the group consisting of AlCl.sub.3, FeCl.sub.3 and FeBr.sub.3, in a chlorinated hydrocarbon solvent at temperatures between -30 and 0.degree. C. in one step to yield compound I.