Patent ID: 8288602

Claim:
A method for preparing substituted fluorenes that comprises the steps of: I. alkylating diphenylmethane with at least 2 equivalents alkylating agent of general formula wherein X is a halogen selected from Cl, Br or I; Ra, Rb and Rc are each independently selected from alkyl, aryl, heteroaryl, cycloalkyl or alkenyl having from 1 to 20 carbon atoms, with the restriction that a carbon atom from each of Ra, Rb and Rc is directly attached to the carbon atom in the presence of a Lewis acid and crystallizing the alkylated product; II. brominating the step I product with 2.01 to 2.05 equivalents of bromine at between 10Â° C. and 20Â° C. in the presence of a Lewis acid or a metal that is able to give Lewis acid in the reaction medium, followed by washing with a solution and recrystallization after separation and drying; III. reacting the product resulting from step II with a reducing agent in the presence of a catalyst consisting of a ligand of general formula wherein Rm, Rn Rp and Rq are each independently selected from hydrocarbyl having from 1 to 30 carbon atoms or any organic substituent with the restriction that a halogen cannot be directly attached to N and wherein any two consecutive R's of the ligand can be joined to make a ring, and wherein E's are the same or different and are each independently selected from C, N, P or B; and a compound of a Group 10 metal.