Dichloromethane → Deacetyldiltiazem

Participants

Reaction Steps

0.2 g of triethylbenzylammonium chloride, 3 g of cis-(+)-2-(4'-methoxyphenyl)-3-hydroxy-2,3-dihydro-1,5-benzothiazepine-4(5H)-one and 6.4 g of barium hydroxide octahydrate were added under vigorous stirring to 60 ml of methylene chloride and 10 ml of water. A solution of 3.2 g of 2-(dimethylamino)-ethyl chloride-hydrochloride in 5 ml of water was added dropwise to the above mixture during 5 minutes. Stirring was continued at room temperature for 1 hour and then at 40° for 24 hours. After cooling to room temperature the aqueous phase was separated and discarded and the methylene chloride was removed under vacuum. (Petroleum ether (40°-60°) was added to the viscous residue with induced crystallisation. The crystals obtained were filtered off and dried under vacuum to yield 3.7 g of cis-(+)-2-(4'-methoxyphenyl)-3-hydroxy-5-(2'-dimethylaminoethyl)-2,3-dihydro-1,5-benzothiazepine-4(5H)-one; m.p.88°-90°; [α]D27 +169 (C=0.25, CH3OH).

Provenance & Evidence