Patent ID: 7473813

Claim:
A method for the preparation of a substituted fluorene comprising: (a) providing a 3,6-disubstituted fluorene characterized by the formula: wherein: R 1 and R 2 are C 1 -C 20 alkyl groups which may be the same or different; (b) reacting said 3,6-disubstituted fluorene group with a brominating agent to produce a 2,7-dibromo-3,6-disubstituted fluorene characterized by the formula: wherein: R 1 and R 2 are as defined above; (c) reacting said 2,7-dibromo-3,6-disubstituted fluorene with a magnesium or zinc-based Grignard reagent characterized by the formula: RMX wherein: R is a C 1 -C 20 alkyl or a C 6 -C 20 alicyclic or aryl group, M is magnesium or zinc and X is a halogen, to produce a 2,7,3,6-tetrasubstituted fluorene characterized by the formula: wherein: R, R 1 , and R 2 are as defined above; or (d) reacting said 2,7-dibromo-3,6-disubstituted fluorene in the presence of a palladium-based catalyst with an aryl boronic acid characterized by the formula: wherein: A r is a phenyl group or a naphthyl group and R a is a C 1 -C 20 alkyl group; to produce a 2,3,6,7-substituted fluorene characterized by the formula: wherein: R 1 , R 2 , R a , and A r are as defined above.