Water → 2-(3-Chloropropyl)-2H-1,2-benzothiazin-4(3H)-one 1,1-dioxide Ethylene Ketal

Participants

Reaction Conditions

Reaction Steps

In 1,2-dimethoxyethane (450 mL) was suspended 60% sodium hydride (2.0 g, 502 mmol.), and then 2H-1,2-benzothiazin-4(3H)-one 1,1-dioxide ethylene ketal (12.06 g, 50 mmol.) was added to the suspension. The suspension was heated to 100° C. for 1 hour under stirring. The reaction liquid was cooled to 50° C., and to this was added a solution of 1-bromo-3-chloropropane (23.62 g, 150 mmol.) in 1,2-dimethoxyethane (50 mL). The mixture was heated to 100° C. for 21 hours under refluxing. The reaction liquid was filtered to remove insolubles and the solvent was evaporated to give a residue. The residue was treated with water and ether, and the organic layer was taken out. The organic solution was washed with water and a saturated aqueous sodium chloride solution, and dried over anhydrous sodium sulfate. The solvent was evaporated to leave the desired compound (8.89 g, yield 56%) as a yellow oil.

Provenance & Evidence