反应详情

To a solution of methyl 2-(3,4-dimethoxyphenyl)acetate SLA 28134 (10.01 g, 47.6 mmol) in propionic anhydride (24.0 mL, 187.2 mmol) at 0° C. in a 500 mL round-bottomed flask equipped with a magnetic stirrer was added HClO4 (ca. 70% solution in water, 4.89 mL, 56.6 mmol) over a period of 30 min. The reaction mixture was then allowed to warm up to RT, stirred for 45 min and diluted with Et2O (450 mL). The solid was filtered and washed several times with Et2O giving 10.5 g of a brown solid. To a suspension of this solid (9.98 g, 29.8 mmol) in H2O (54 mL) in a 500 mL round-bottomed flask equipped with a magnetic stirrer and cooled in an ice bath was added dropwise concentrated NH4OH (81 mL). After complete addition, the ice bath was removed and the reaction mixture was stirred at RT for 1 h, after which the solid was filtered and washed with plenty of water until neutral pH of the filtrate. The solid was dried under vacuum in presence of P2O5 to give 1-ethyl-6,7-dimethoxyisoquinolin-3-ol SLA 28136 as a yellow solid (5.30 g, 48% yield).

1. filtrationThe solid was filtered
2. washwashed several times with Et2O giving 10.5 g of a brown solid
3. customequipped with a magnetic stirrer
4. temperaturecooled in an ice bath
5. additionAfter complete addition
6. customthe ice bath was removed
7. stirringthe reaction mixture was stirred at RT for 1 h
8. filtrationafter which the solid was filtered
9. washwashed with plenty of water until neutral pH of the filtrate
10. dry with materialThe solid was dried under vacuum in presence of P2O5