Bromine → 3-Bromo-7-(1,1-dimethoxyethyl)imidazo[1,2-a]pyrimidine

Participants

Reaction Conditions

Reaction Steps

A mixture of 7-(1,1-dimethoxyethyl)imidazo[1,2-α]pyrimidine (5.3 g, 26 mmol), potassium bromide (3.1 g, 26 mmol) and sodium acetate (3.2 g, 39 mmol) in methanol (50 ml) was cooled to 0° C. before dropwise addition of bromine (4.5 g, 28 mmol) over 10 min. After stirring at 0° C. for a further 15 min the reaction was treated with 1M sodium sulphite solution (5 ml) and the solvent removed in vacuo. The residue was treated with dichloromethane (100 ml) then saturated sodium hydrogencarbonate solution (100 ml) was added. After stirring vigorously for 10 min the organic layer was collected, washed with 1M sodium sulphite solution (100 ml), water, brine, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. Trituration of the residue with diethyl ether furnished 3-bromo-7-(1,1-dimethoxyethyl)imidazo[1,2-α]pyrimidine (5.05 g, 69%) as a cream-coloured solid: δH (360 MHz, CDCl3) 1.70 (3H, s), 3.28 (6H, s), 7.43 (1H, d, J 7), 7.82 (1H, s), 8.39 (1H, d, J 7).

Provenance & Evidence