N-bromobutanimide → 4-Bromo-6-methoxy-3-methyl-1,2-dihydroisoquinolin-1-one

Participants

Reaction Steps

NBS (6.9 g, 40 mmol) is added in one portion to ice-cold suspension of 6-methoxy-3-methyl-2H-isoquinolin-1-one (6.7 g, 35 mmol) in AcOH (100 ml). The ice bath is removed, and after 1 h, the mixture is concentrated in vacuo. The residue is diluted with water (40 ml) and basified with 10N—NaOH to pH 12. The resulting white solid is filtered and dried to give 9.3 g of 4-bromo-6-methoxy-3-methyl-2H-isoquinolin-1-one. 1H NMR (CDCl3) 8.10 (d, 1H), 7.14 (s, 1H), 7.08 (d, 1H), 3.89 (s, 3H), 2.37 (s, 3H).

Provenance & Evidence