Tributyltin Chloride → 3-Tributylstannylimidazo[1,2-alpha]pyrimidine

To a cooled (−78° C.) solution of 3-bromoimidazo[1,2-α]pyrimidine (500 mg, 2.5 mmol) in tetrahydrofuran (20 ml) was added isopropylmagnesium chloride (1.39 ml of a 2.0M solution in tetrahydrofuran, 2.78 mmol). After stirring for 5 min tri-n-butyltin chloride (0.8 ml, 2.90 mmol) was added and the reaction stirred for 10 min at −78° C. then allowed to warm to ambient temperature to give a solution of 3-tributylstannylimidazo[1,2-α]pyrimidine in tetrahydrofuran: m/z (ES+) 407, 409, 411 (M++H).