Patent ID: 6472345
Filing Date: 2002-10-29
Classification: C07B,C07C

Abstract:
A process for halogenation of an activated methylene or methine compound with at least equimolar amounts of an electrophilic halogenation reagent, which comprises reacting said activated methylene or methine compound with said electrophilic halogenation reagent in the presence of a catalytic amount of a titanium compound of the formula I or of a titanium compound of the formula IIR1TiX1X2X3â€ƒâ€ƒ(I), R2R3TiX1X2â€ƒâ€ƒ(II), in whichR1 is chlorine, bromine or iodine, a substituted or unsubstituted cyclopentadienyl or indenyl, and X1, X2 and X3 are, independently of one another, chlorine, bromine or iodine, or X1, X2 and X3 are an organic sulfonate group where R1 is a substituted or unsubstituted cyclopemtadienyl or indenyl; R2 and R3 are a substituted or unsubtitued cyclopentadienyl or indenyl, R2 and R3 together are a substituted or unsubstituted and bridged or unbridged biscyclopentadienyl or bisindenyl, or R2 and R3 together are a substituted or unsubstituted 1,3-, 1,4- or 1,5-diolate, and X1 and X2 are, independently of one another, chlorine, bromine or iodine or an organic sulfonate group.