Methane → 8-Fluoro-11(1-ethoxycarbonyl-4-piperidylidene)-6,11-dihydro-5H-benzo[5,6]cyclohepta[1,2-b]pyridine

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Reaction Conditions

Reaction Steps

Ethyl chloroformate (8.5 mL, 9.65 g, 0.089 mole) is slowly added at 80° C. to a solution of 8-fluoro11-(1-methyl-4-piperidylidene)-6,ll-dihydro-5H-benzo[5,6)cyclohepta[1,2-b]pyridine (5.4 g, 0.0175 mole) and triethylamine (3.6 mL, 2.61 g, 0.026 mole) in 60 mL of toluene. Following complete addition, the temperature is maintained at 80° C. for 1 hour. The reaction mixture is treated with charcoal, filtered, and concentrated to a residue. Following purification by silica gel chromatography and crystallization from pentane, 4.10 g (0.011 mole) of 8-fluoro-6,11-dihydro-11-(1- ethoxycarbonyl-4-piperidylidene)-5H-benzo[5,6]cyclohepta[1,2-b]pyridine is obtained in 63% yield. 8-bromo, 8,9-dichloro, 9-chloro, and 9-fluoro analogs of this 8-fluoro-11-(1-ethoxycarbonyl-4piperidylidene) compound can be prepared.

Provenance & Evidence