Ammonia → Methyl 5-aMino-6-broMopicolinate

Participants

Reaction Steps

2.0 ml of hydrogen peroxide solution (32% strength) were added to methyl 5-aminopyridine-2-carboxylate (2.0 g, 13.15 mmol) and 30 ml of 48% strength hydrobromic acid, and the reaction was stirred at room temperature for two hours. Another 0.32 ml of hydrogen peroxide solution were then added, and the mixture was stirred for a further hour. The mixture was adjusted to pH 8 by addition of concentrated ammonia solution with ice cooling and extracted three times with in each case 60 ml of ethyl acetate. The organic phase was dried over sodium sulphate, concentrated on a rotary evaporator and chromatographed on silica gel (mobile phase: cyclohexane/ethyl acetate). This gave 1.32 g of the desired product (42.3% of theory).

Provenance & Evidence