Methanol → 3-Methylisoquinolin-7-ol

7-Methoxy-3-methylisoquinoline (15 g, 89 mmol, 1 equiv.) was dissolved in methylene chloride (150 mL). A 1.0 M solution of BBr3 in methylene chloride (240 mL, 240 mmol, 2.7 equiv.) was added slowly to this solution at room temperature observing a slight exotherm. This solution was stirred at room temperature for 2.5 hours. After cooling to 0° C., methanol (150 mL) was added slowly to quench the reaction. The solution was stirred for an additional 15 minutes. The solution was concentrated under reduced pressure and treated with methanol (150 mL) and concentrated under reduced pressure. The resulting oil was treated with saturated aqueous sodium bicarbonate slowly with stirring until a pH˜7-8 was achieved. The solid resulting was collected under vacuum filtration and was washed with water (300 mL) and methylene chloride (200 mL) giving a tan solid which was dried in a vacuum oven at 50° C. overnight to give 3-methylisoquinolin-7-ol (13.1 g, 92% yield).

1. temperatureAfter cooling to 0° C.
2. customto quench
3. customthe reaction
4. stirringThe solution was stirred for an additional 15 minutes
5. concentrationThe solution was concentrated under reduced pressure
6. additiontreated with methanol (150 mL)
7. concentrationconcentrated under reduced pressure
8. additionThe resulting oil was treated with saturated aqueous sodium bicarbonate slowly
9. stirringwith stirring until a pH˜7-8
10. customThe solid resulting
11. filtrationwas collected under vacuum filtration
12. washwas washed with water (300 mL) and methylene chloride (200 mL)
13. customgiving a tan solid which
14. customwas dried in a vacuum oven at 50° C. overnight

ORD record

ord-3c20d432e836420293b77f243e1b3bf5

Source dataset

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09340527B2