Potassium Carbonate → (+)-cis-2-(4-methoxyphenyl)-3-(2-chloro-4-nitrobenzoyloxy)-5-[2-(N-methyl-N-ethylamino)ethyl]-2,3-dihydro-1,5-benzothiazepin-4(5H)-one oxalate

Participants

Reaction Steps

970 mg of (-)-cis-2-(4-methoxyphenyl)-3-(2-chloro-4-nitrobenzoyloxy)-2,3-dihydro-1,5-benzothiazepin-4(5H)-one are dissolved in 20 ml of acetone, and 690 mg of potassium carbonate and 410 mg of 2-(N-methyl-N-ethylamino)ethyl chloride hydrochloride are added thereto. The mixture is refluxed for 3 hour under stirring. After the reaction, the mixture is evaporated under reduced pressure to remove solvent. Ethyl acetate is added to the residue, and the mixture is washed with water. The ethyl acetate solution is dried and evaporated under reduced pressure to remove solvent. 180 mg of oxalic acid and 15 ml of ethanol are added to the residue, and the mixture is heated to make a clear solution. The clear solution is allowed to stand. Crystalline precipitates are collected by filtration and dried, whereby 1.20 g of (+)-cis-2-(4-methoxyphenyl)-3-(2-chloro-4-nitrobenzoyloxy)-5-[2-(N-methyl-N-ethylamino)ethyl]-2,3-dihydro-1,5-benzothiazepin-4(5H)-one oxalate are obtained as colorless needles. Yield: 91%.

Provenance & Evidence