Acetic Anhydride → 8-methylisoquinolin-1(2H)-one

A solution of 8-methylisoquinoline 2-oxide (1.4 g, 8.8 mmol) in Ac2O (20 mL) was refluxed for 3 hours. The mixture was concentrated under vacuum and the residue was dissolved in MeOH (20 mL). To the reaction mixture was added aq. NaOH (20 mL, 1M). The mixture was refluxed for 1 hour and stirred at room temperature for 10 hours. The mixture was concentrated under vacuum. The residue was diluted with water (20 mL) and extracted with EtOAc (3×20 mL). The combined organic layers were washed with brine (2×10 mL), dried over Na2SO4, filtered, and concentrated under vacuum. The residue was purified by column chromatography (petroleum ether/EtOAc, 3:1) to give 8-methylisoquinolin-1(2H)-one (76a, 1 g, 71%) as a yellow solid.

1. concentrationThe mixture was concentrated under vacuum
2. dissolutionthe residue was dissolved in MeOH (20 mL)
3. additionTo the reaction mixture was added aq. NaOH (20 mL, 1M)
4. temperatureThe mixture was refluxed for 1 hour
5. concentrationThe mixture was concentrated under vacuum
6. additionThe residue was diluted with water (20 mL)
7. extractionextracted with EtOAc (3×20 mL)
8. washThe combined organic layers were washed with brine (2×10 mL)
9. dry with materialdried over Na2SO4
10. filtrationfiltered
11. concentrationconcentrated under vacuum
12. customThe residue was purified by column chromatography (petroleum ether/EtOAc, 3:1)

ORD record

ord-b55298fcbf284c3db4965980267af653

Source dataset

uspto-grants-2015_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09040515B2