Cesium carbonate → 5-Bromo-1-(cyclopropylmethyl)-3-methyl-1,3-dihydro-2,1,3-benzothiadiazole 2,2-dioxide

Participants

Reaction Conditions

Reaction Steps

To a round bottom flask was added 6-bromo-1-methyl-1,3-dihydro-2,1,3-benzothiadiazole 2,2-dioxide (1-3) (5.32 g, 20.2 mmol), anhydrous NMP (10 mL), anhydrous 1,4 Dioxane (100 mL), cesium carbonate (13.2 g, 40.4 mmol), followed by (bromomethyl)cyclopropane (3.00 g, 22.2 mmol). The reaction mixture was then heated to 100° C. while stirring in a hot oil bath for 18 hours. The crude reaction mixture was then cooled to room temperature, then suspended in ethyl acetate and washed with a saturated solution of sodium bicarbonate, followed by water, then brine, dried over sodium sulfate, filtered, and concentrated. The resulting residue was purified by silica gel chromatography (0-40% EtOAc/Hex) to give 5-bromo-1-(cyclopropylmethyl)-3-methyl-1,3-dihydro-2,1,3-benzothiadiazole 2,2-dioxide (1-4) as a tan solid. HRMS (M+H)+: observed=316.9953, calculated=316.9954.

Provenance & Evidence