反应详情

Catalytic reduction of 10 g of 3-(o-nitrophenyl)thio-2(R)-phthalimidopropionic acid in 300 ml of methanol is carried out at ordinary temperature and under atmospheric pressure using 5% palladium-carbon as catalyst. After absorption of the calculated amount of hydrogen, the catalyst is removed and the methanol is evaporated off under reduced pressure. The residue is crystallized from a mixture of ether and petroleum ether to give 8.4 g of 3-(o-aminophenyl)thio-2(R)-phthalimidopropionic acid as pale yellow crystals. To a stirred solution of 8.4 g of this product in 50 ml N,N-dimethylformamide is added dropwise 5.5 g of diethyl phosphorocyanidate at ice bath temperature. After the reaction mixture is stirred for 5 minutes, 2.28 g of triethylamine, is added dropwise at ice bath temperature. The resulting mixture is stirred for 30 minutes in an ice bath and for another 1 hour at room temperature, diluted with 200 ml of water and allowed to stand overnight. The deposited solid is collected by filtration and purified by silica gel column chromatography (dichloromethane:ethyl acetate=2:1 ) to give 5.4 g of 3(R)-phthalimido-2,3-dihydro-1,5(5H)-benzothiazepin-4-one as colorless prisms.

1. customAfter absorption of the calculated amount of hydrogen
2. customthe catalyst is removed
3. customthe methanol is evaporated off under reduced pressure
4. customThe residue is crystallized from a mixture of ether and petroleum ether