Methanol → 6-Bromo-1,2,3,4-tetrahydro-[1,8]naphthyridin-4-ol

Participants

Reaction Conditions

Reaction Steps

7-Bromo-1,2,3,4-tetrahydro-[1,8]naphthyridin-4-ol (460 mg) was dissolved in anhydrous tetrahydrofuran (25 mL) and cooled to −78° C. A solution of n-butyllithium in tetrahydrofuran was added (1.6 M, 8.5 mL) (5-7 equiv.) and the reaction was warmed slowly to room temperature. After 2-5 hours, methanol (2 mL) was added and the contents were concentrated to dryness. The residue was dissolved in a mixture of dichloromethane and acetic acid (1:1, v/v, 20 mL) and N-bromosuccinimide (450 mg) (1.2 equiv.) were added. After 45 minutes, the mixture was concentrated to dryness onto silica gel, and purified by silica gel chromatography to give the title compound as yellow solids (25-65% yield). M.p. 125-128° C., LCMS: m/z=229 (M+H+), 1H-NMR (DMSO-d6, 400 MHz) δ 1.72 (m, 2H), 3.25 (m, 2H), 4.56 (m, 1H), 5.33 (d, J=5.0 Hz, 1H), 6.8 (bs, 1H), 7.47 (d, J=2.5 Hz, 1H), 7.87 (d, J=2.5 Hz, 1H).

Provenance & Evidence