27104-72-9

67-56-1

486-73-7

27104-72-9

To a solution of isoquinoline-1-carboxylic acid (10 g, 57.74 mmol) in methanol (150 mL) was slowly added concentrated sulfuric acid (15 mL) at 0 °C. The reaction mixture was gradually warmed to 65 °C and stirred continuously at this temperature for 24 hours. Upon completion of the reaction, the mixture was cooled to room temperature. Subsequently, the reaction mixture was partitioned between dichloromethane and saturated aqueous sodium bicarbonate solution. The organic layer was separated and dried with anhydrous sodium sulfate. The solvent was removed by evaporation under reduced pressure to give methyl isoquinoline-1-carboxylate as a yellow oil product (11.2 g, 100% yield). The product was analyzed by ESI-MS and the m/z [M + H]+ was 188.