Patent ID: 6232516
Filing Date: 2001-05-15
Classification: C07C

Abstract:
A process for selectively substituting one or more substituents onto a cyclopentadiene ring to thereby increase the number of substituents on the five-member ring, said process comprising the step of:reacting a compound comprising a cyclopentadiene ring with at least one first substituting compound comprising a first substituting group and a first halide to thereby substitute the first substituting group onto the cyclopentadiene ring whereby a substituted compound comprising a cyclopentadiene ring having an increased number of substituents on the cyclopentadiene ring is obtained, said reacting step occurring in a reaction mixture comprising at least one phase transfer catalyst, an organic phase and a first aqueous phase, and at least one first base in a molar ratio of from about 5 to about 30 to the compound comprising the cyclopentadiene ring, andcomprising the at least one first substituting compound in a quantity, expressed in moles, which corresponds to a stoichiometric amount with no more than 10 mol % excess corresponding to the desired multiplicity of substitution on the cyclopentadiene ring.