n-Butyllithium (2.6M in toluene; 0.70 mL) was added to a solution of N,N-diisopropylamine (184 mg) in THF (30 mL) at −78° C. After 10 minutes, 4-butoxy-N-[4-(3-dimethylaminopyrrolidin-1-yl)-3-fluorophenyl]-2-methylbenzamide (0.30 g) was added, and the mixture was stirred at −78° C. for 30 minutes and then warmed to −20° C. DMF (53 mg) was added, and the reaction mixture was hydrolyzed after a further 30 minutes with hydrochloric acid. The reaction mixture was partitioned between sodium carbonate solution and ethyl acetate. The organic phase was dried over sodium sulfate and concentrated. The residue was purified by preparative HPLC. The product with the molecular weight of 423.54 (C25H30FN3O2) was obtained in this way; MS (ESI): 424 (M+H+).
