Dimethylamine → 2,6-Dibromo-3,5-dihydroxy-4[(dimethylamino) methylene]-benzoic Acid

Participants

Reaction Conditions

Reaction Steps

To a stirred mixture of 37% of aqueous formaldehyde solution (2 mmol), absolute ethanol (0.4 mL), and glacial acetic acid (0.8 mL) was added 40% of aqueous dimethylamine (2 mmol) solution under ice bath (25° C.). The ice bath was removed and 2,6-Dibromo-3,5-dihydroxybenzoic Acid (1 mmol) was added over a period of 2 min. The mixture became darkened, and after 5 min a white solid began to appear. The mixture was stirred at 25° C. for 24 h and then at 0° C. for 2 h to allow complete precipitation of product. The precipitate was washed with ice-cold acetone (2×0.5 mL), dried under oil pump to give 2,6-Dibromo-3,5-dihydroxy-4[(dimethylamino) methylene]-benzoic Acid (98%): 1H NMR (DMSO-d6) δ 3.92 (s, 2H), 2.41 (s, 6H).

Provenance & Evidence