Methyl iodide → Methyl 4-bromo-5,6,7,8-tetrahydro-7-methyl-8-oxo-7-isoquinolinecarboxylate

Participants

Reaction Steps

To a stirred solution of (rac)-methyl 4-bromo-8-oxo-5,6,7,8-tetrahydroisoquinoline-7-carboxylate (3.5 g, 12.3 mmol) (intermediate A-1[B]) in DMF (10 mL) and THF (50 mL) was added 60% NaH (750 mg, 18.5 mmol) in portions at 0° C. The reaction mixture was stirred at 0° C. for 15 min before methyl iodide (1.6 mL, 24.6 mmol) was added and the resulting reaction mixture was allowed to warm up to room temperature and stirred over night. The reaction mixture was then diluted with water (10 mL) and extracted with EtOAc (2×). Combined organics were washed with brine, dried over Na2SO4, filtered and evaporated to dryness. The residue was purified by silica gel flash chromatography eluting with a 0 to 30% EtOAc-heptane gradient to give the title compound (3.3 g, 90% yield) as a light yellow solid. MS: 297.9 & 299.9 (M+H)+.

Provenance & Evidence