Methanesulfonic Acid → 6-Bromo-3,4-dihydro-2H-isoquinolin-1-one

Participants

Reaction Steps

5-bromo-2,3-dihydro-1H-inden-1-one (1K1) (9.48 mmol, 2 g) was dissolved in DCM (35 ml) and methane sulfonic acid (95 mmol, 9.11 g) was added. The reaction mixture was cooled to 0° C. before portionwise addition of sodium azide (28.4 mmol, 1.85 g). Once addition was complete the mixture was allowed to warm to room temperature and stirred overnight. The reaction mixture was partitioned between DCM and NaOH (2M, 50 ml). The phases were separated and the aqueous layer was extracted twice more with DCM. The combined organics were washed with water and brine, dried (MgSO4) and evaporated to dryness before purification on silica eluting with 75-100% EtOAc/heptane to give 6-bromo-3,4-dihydroisoquinolin-1(2H)-one (1K2) 919 mg (42%) 1H NMR (400 MHz, CDCl3) δ 7.93 (d, 1H) 7.49 (d, 1H) 7.40 (s, 1H) 6.36 (bs, 1H) 3.58 (t, 2H) 2.99 (t, 2H).

Provenance & Evidence