反应详情

温度

110 °C

To a solution of 6,7-dimethoxy-1-methylisoquinolin-3-ol CCH 18060 (51 mg, 233 μmol) in toluene (1 mL) in a 2 mL microwave vial equipped with a magnetic stirrer was added a 2 N aq. KOH solution (0.12 mL, 0.24 mmol) at RT followed by benzyl bromide (30 mg, 251 μmol) and the mixture was stirred at 110° C. for 15 min under microwave irradiation. After cooling to RT, the mixture was diluted with H2O (5 mL) before extraction with CH2Cl2 (20 mL). The organic phase was isolated and the aqueous phase was acidified with AcOH (5 drops) and then further extracted with CH2Cl2. The organic phase was combined, washed with brine (10 mL), dried over Na2SO4, filtered and concentrated at 40° C. under vacuum. Purification by column chromatography (SiO2, eluent CH2Cl2:MeOH=100:0 to 95:5) gave, after evaporation and drying, 4-benzyl-6,7-dimethoxy-1-methylisoquinolin-3-ol. 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 0.2 M HCl solution in MeOH (1 mL). The reaction mixture was stirred for 5 min at RT and concentrated at 40° C. under vacuum to afford 4-benzyl-6,7-dimethoxy-1-methylisoquinolin-3-ol hydrochloride 1 as a pale brown solid (31 mg, 38% yield).

1. temperatureAfter cooling to RT
2. customThe organic phase was isolated
3. extractionfurther extracted with CH2Cl2
4. washwashed with brine (10 mL)
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated at 40° C. under vacuum
8. customPurification by column chromatography (SiO2, eluent CH2Cl2:MeOH=100:0 to 95:5)
9. customgave
10. customafter evaporation
11. customdrying
12. dissolutionThis free base was dissolved in MeOH (2 mL) in a 10 mL round-bottomed flask
13. customequipped with a magnetic stirrer before addition of a 0.2 M HCl solution in MeOH (1 mL)
14. stirringThe reaction mixture was stirred for 5 min at RT
15. concentrationconcentrated at 40° C. under vacuum