Phosphinic Acid → 3-Bromo-5-methoxybenzoic acid

Participants

Reaction Steps

To a solution of 2-amino-5-bromo-3-(methyloxy)benzoic acid (16.40 g, 66.65 mmol) in H2O (80 mL), conc. HCl (30 mL) and THF (5 mL) were added at 0° C. The reaction was stirred for 30 min, and then NaNO2 (14.00 g, 202.91 mmol) was cautiously added to the solution. After the reaction mixture had stirred for 2 h, H3PO2 (22.00 g, 333.35 mmol) was cautiously added to the solution. The reaction was kept stirring overnight at the room temperature (monitored by TLC), and filtered and rinsed with water (50 mL×2). The formed precipitate was dried to afford 3-bromo-5-(methyloxy)benzoic acid (9.60 g, 62%). 1H NMR (400 MHz, CDCl3): δ 7.46 (t, J=1.6 Hz, 1 H), 7.31 (q, J=16.8 Hz, 1 H), 7.21 (t, J=16.8 Hz, 1 H), 3.84 (s, 1 H).

Provenance & Evidence