Ethanol (1.8 mL) was added to 6-(4-chloro-3-isopropyl-1-methyl-1H-pyrazol-5-yl)-4-(3,3-dimethylpiperidin-1-yl)-2-(3-methyl-1-tosyl-1H-indol-4-yl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine (74 mg, 0.108 mmol) in a microwave vial. Next, KOH (61 mg, 1.08 mmol) was added followed by 28% aqueous ammonium hydroxide (0.6 mL, 4.35 mmol). The vessel was sealed and heated via microwave irradiation at 100° C. for 75 minutes. The reaction mixture was cooled to room temperature and diluted with dichloromethane and water. The layers were separated and the organic layer was dried by passing through a phase separator. The eluent was concentrated and the resulting residue was purified by reverse phase HPLC (20-55% MeCN/Water (0.1% TFA)). The eluent from the HPLC was neutralized with saturated aqueous sodium bicarbonate and extracted with dichloromethane. The organic extract was dried by passing through a phase separator and concentrating to provide 6-(4-chloro-3-isopropyl-1-methyl-1H-pyrazol-5-yl)-4-(3,3-dimethylpiperidin-1-yl)-2-(3-methyl-1H-indol-4-yl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine.
