3-Methylisoquinoline → 4-Bromo-3-methyl-isoquinoline

Participants

Reaction Conditions

Reaction Steps

In a 40 mL screw-top vial with a stirbar was added 3-methyl-isoquinoline (6.00 g, 41.9 mmol) in hydrobromic acid (6 mL), followed by the dropwise addition of bromine (2.2 mL, 42.7 mmol, 1.02 eq). The entire suspension was heated at 100-120° C. for 24 hr. The reaction mix was cooled and diluted with DCM (100 mL) and 1N NaOH added slowly to neutralize the reaction. The organic layer was collected and dried over Na2SO4 and concentrated to a dark orange oil. The crude reaction was purified using Biotage MPLC system (40M column size, 0-15% Ethyl Acetate/Heptane over 30CV) giving a tan crystalline solid as the desire product (3.48 g, 14.57 mmol, 34.8%). 1H NMR (CDCl3, 400 MHz): δ 9.01 (s, 1H), δ 8.12-8.10 (d, 1H), δ 7.87-7.85 (d, 1H), δ7.72-7.68 (dt, 1H), δ 7.54-7.50 (dt, 1H), δ 2.80 (s, 3H); LRMS (m/z): 224, 222 (M+H).

Provenance & Evidence