Triphenylphosphine → 3-(2-bromoethyl)-1-(2-fluorophenyl)-3,4-dihydro-1H-2,1,3-benzothiadiazine 2,2-dioxide

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Reaction Steps

A solution of 1-(2-fluorophenyl)-3,4-dihydro-1H-2,1,3-benzothiadiazine 2,2-dioxide (0.46 g, 1.7 mmol) in tetrahydrofuran (20 mL) was cool to 0° C. and treated with triphenylphosphine (0.65 g, 2.5 mmol), bromoethanol (0.25 mL, 3.5 mmol) and diisopropyl azodicarboxylate (0.5 mL, 2.6 mmol). After the final addition, the reaction mixture was warmed to room temperature for 2 h, evaporated to a brown oil. The crude product residue was purified by flash chromatography (SiO2, 3-50% ethyl acetate/heptane) to afford 3-(2-bromoethyl)-1-(2-fluorophenyl)-3,4-dihydro-1H-2,1,3-benzothiadiazine 2,2-dioxide (0.44 g, 63%) as a white solid:

Provenance & Evidence