Methyl iodide → HCID 60164574, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-(3,4-dimethoxybenzyl)-6,7-dimethoxy-1-methylisoquinolin-3-ol (compound 2 free base, 60 mg, 162 μmol), cesium carbonate (70 mg, 215 μmol) and iodomethane (13 μL, 208 μmol) in dry DMF (2 mL) in a 5 mL microwave vial equipped with a magnetic stirrer was stirred at 90° C. for 22 min under microwave irradiation. After cooling to RT, the mixture was diluted with Et2O (50 mL) before washing with water (10 mL) then with brine (10 mL), drying over Na2SO4, filtration and concentration at 40° C. under vacuum. Purification by column chromatography (SiO2, eluent cyclohexane:EtOAc=100:0 to 75:25) gave 4-(3,4-dimethoxybenzyl)-3,6,7-trimethoxy-1-methylisoquinoline as a colorless oil (33 mg). This free base was dissolved in MeOH (2 mL) in a 10 mL round-bottomed flask equipped with a magnetic stirrer before addition of a 0.15 M HCl solution in MeOH (1.5 mL). The reaction mixture was stirred for 5 min at RT and concentrated at 40° C. under vacuum. The solid was then washed with Et2O to afford, after drying, 4-(3,4-dimethoxybenzyl)-3,6,7-trimethoxy-1-methylisoquinoline hydrochloride 3 as a pale brown solid (23 mg, 34% yield).

Provenance & Evidence