To a solution of 7-cyclopentyl-2-(5-piperazin-1-yl-pyridin-2-ylamino)-7H-pyrrolo[2,3-d]pyrimidine-6-carboxylic acid dimethylamide hydrochloride (150 mg, 0.318 mmol) and potassium carbonate (132 mg, 0.955 mmol) in acetonitrile (3 mL) and DMF (2 mL) is added 1-bromo-2-fluoroethane (0.035 mL, 0.478 mmol) and the reaction mixture is heated to 80° C. for 24 h in a sealed reaction vial. Upon cooling, the reaction mixture is partitioned between dichloromethane and water. The organic layer is separated and the aqueous layer extracted further with dichloromethane. The combined organics are ished with brine, dried (MgSO4), filtered and concentrated. The crude product is purified using silica gel chromatography (0 to 10% methanol/dichloromethane) to give 7-cyclopentyl-2-{5-[4-(2-fluoro-ethyl)-piperazin-1-yl]-pyridin-2-ylamino}-7H-pyrrolo[2,3-d]pyrimidine-6-carboxylic acid dimethylamide (84 mg, 55%) as an off white solid.
