Hydrochloric Acid → 4-amino-1-((8-methyl-1-oxo-2-o-tolyl-1,2-dihydroisoquinolin-3-yl)methyl)-1H-pyrazolo[3,4-d]pyrimidine-3-carboxylic acid

Participants

Reaction Steps

To a stirred solution of 4-amino-1((8-methyl-1-oxo-2-o-tolyl-1,2-dihydroisoquinolin-3-yl)methyl)-1H-pyrazolo[3,4-d]pyrimidine-3-carbaldehyde (compound 4502) (400 mg, 0.94 mmol) in t-BuOH (1.8 mL), a solution of NaH2PO4 (3.90 g, 28.27 mmol) in water (4.8 mL), methyl-2-butene (1.0 mL) and (dropwise) a solution of NaClO2 (767 mg, 6.78 mmol) in water (4.8 mL) were added sequentially. The mixture was stirred at RT for 3 h under an argon atmosphere. The pale yellow solution was acidified with aqueous HCl solution (2 M, 4 mL) to PH=2 and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous Na2SO4 and filtered. The filtrate was concentrated in vacuo, and the residue was triturated with anhydrous ethyl ether and ethyl acetate. The solid was collected by filtration to afford the desired product, 4-amino-1-((8-methyl-1-oxo-2-o-tolyl-1,2-dihydroisoquinolin-3-yl)methyl)-1H-pyrazolo[3,4-d]pyrimidine-3-carboxylic acid (compound 4601) (200 mg, 47% yield) as a yellow solid.

Provenance & Evidence