4-Bromopyrazole → 4-Bromo-1-(oxan-4-yl)-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

4-bromo-1H-pyrazole (1 eq, 3.92 mmol, 0.5 g) is dissolved in dry DMF (5 ml) under an inert atmosphere of nitrogen. The reaction mixture is cooled down to −10° C. and sodium hydride (1 eq, 3.92 mmol, 0.157 g) is added portionwise. After 15 mins at 0° C., the reaction was warmed to R.T and stirred for 30 mins at R.T. A solution of methane sulfonic acid tetrahydro-pyran-4-yl ester (Intermediate B18, step1) (1 eq, 3.92 mmol, 0.5 g) in DMF (5 ml) is added and the reaction mixture is stirred at 95° C. overnight. The reaction mixture is quenched at 0° C. with water and extracted with DCM. This organic portion is washed with water and brine, dried over MgSO4, filtered and concentrated in vacuo. The resulting solid is triturated with MeOH and the solid filtered to afford the title compound; [M+H]+ 231/233.

Provenance & Evidence