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

Participants

Reaction Steps

To a suspension of 2.20 g (50 mmol) of 60% sodium hydride in 100 ml of DMF, a solution of 12.06 g (50 mmol) of 3,4-dihydro-2H-1,2-benzothiazin-4-one 1,1-dioxide ethylene acetal in 50 ml of DMF was added under ice cooling and stirring. The reaction mixture was stirred for 30 minutes at 0° C. and then for further one hour at room temperature. Under ice cooling, a solution of 16.95 g (150 mmol) of 1,3-dichloropropane in 50 ml of DMF was added to the reaction mixture, followed by stirring for 17 hours at room temperature. The post-treatment and purification were conducted as in Example 10, whereby 13.41 g of the title compound were obtained (yield: 84%).

Provenance & Evidence