Sodium Bicarbonate → 3,4-Dihydroxy-5-nitrobenzoic acid

Participants

Reaction Steps

A solution of sodium chlorite (47.6 g, 526 mmol) in water (350 mL) was added drop wise to a solution of 3,4-dihydroxy-5-nitrobenzaldehyde (68.8 g, 376 mmol) and sodium dihydrogen phosphate (45.1 g, 376 mmol) in DMSO/H2O mixture (375 mL/150 mL) at room temperature over 1.5 h. The reaction mixture was stirred at room temperature for 1 h and poured into a separatory funnel containing a 5% solution NaHCO3 (500 mL). The product was extracted with dichloromethane (3×100 mL). The water layer was acidified with concentrated HCl to pH˜1 and extracted with ether (3×250 mL). The combined organic layers were washed with brine (200 mL), dried over Na2SO4, and evaporated to afford the desired acid (70.3 g, 353 mmol, 94% yield).

Provenance & Evidence