Trifluoroacetic acid → (3-Aminopiperidin-1-yl)(2-(1-ethyl-1H-pyrrolo[2,3-b]pyridin-2-yl)-1-methyl-1H-benzo[d]imidazol-5-yl)methanone

To a solution of tert-butyl(1-(2-(1-ethyl-1H-pyrrolo[2,3-b]pyridin-2-yl)-1-methyl-1H-benzo[d]imidazole-5-carbonyl)piperidin-3-yl)carbamate (104 mg, 0.207 mmol) in dichloromethane (DCM) (1 mL) was added TFA (0.367 mL, 4.76 mmol) and the reaction stirred at room temperature for 2 h. LCMS (A1) showed no desired product but reaction had progressed to 1 major product. The reaction mixture was concentrated in vacuo to afford a colourless oil. This was dissolved in methanol and loaded onto an SCX cartridge (5 g). It was eluted with methanol (3 column volumes) and product eluted as free base with 2M ammonia in methanol. The filtrate from the ammonia fractions was concentrated in vacuo to yield a yellow solid—(3-aminopiperidin-1-yl)(2-(1-ethyl-1H-pyrrolo[2,3-b]pyridin-2-yl)-1-methyl-1H-benzo[d]imidazol-5-yl)methanone (81 mg, 0.201 mmol, 97% yield).