Acetic Acid → 4-Bromo-5,6,7,8-tetrahydroisoquinolin-8-OL

Participants

Reaction Conditions

Reaction Steps

A suspension of 4-bromo-6,7-dihydroisoquinolin-8(5H)-one (intermediate A-1[C]) (2.135 g, 9.44 mmol) in MeOH (18.9 mL) was cooled to 0° C. and treated with NaBH4 (357 mg, 9.44 mmol) in 5 portions over 30 min. The reaction was stirred for ¾ h at 0° C., then AcOH was added dropwise until pH ˜5-6 and the reaction mixture was evaporated. The residue was diluted with water and poured on aq. sat. NaHCO3-solution followed by extraction with EtOAc (3×). The organic layers are washed once with aq. sat. NaHCO3 and aq. 10% NaCl solution, dried over Na2SO4 and concentrated in vacuo. The residue was precipitated with CH2Cl2/n-pentane to afford the title compound (1.98 g, 92%) as dark brown viscous oil. MS: 227 (M+, 1 Br).

Provenance & Evidence