[NH:1]1[CH2:5][CH2:4][CH2:3][CH2:2]1.[C:6]([O:10][C:11]([N:13]1[CH2:18][CH2:17][S:16][CH2:15][CH:14]1[C:19](O)=[O:20])=[O:12])([CH3:9])([CH3:8])[CH3:7].P(C#N)([O-])(OCC)=O.O>O1CCCC1>[C:6]([O:10][C:11]([N:13]1[CH2:18][CH2:17][S:16][CH2:15][CH:14]1[C:19]([N:1]1[CH2:5][CH2:4][CH2:3][CH2:2]1)=[O:20])=[O:12])([CH3:9])([CH3:8])[CH3:7]
followed by a solution of pyrrolidine (2.0 ml) in 10 ml of tetrahydrofuran, was added at 0° C. under a stream of nitrogen to a solution of 5.0 g of 4-(t-butoxycarbonyl)thiomorpholine-3-carboxylic acid in 100 ml of tetrahydrofuran. After the mixture had been stirred for I hour, a solution of 3.6 g of ethyl cyanophosphate in 10 ml of tetrahydrofuran was added to the mixture and the mixture was stirred for 5 hours. Water was added to the reaction mixture and the mixture was extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate and the solvent was concentrated under reduced pressure. The residue was recrystallized from ethyl acetate/hexane to yield 461 g (74%) of 4-(t-butoxycarbonyl)-3-(pyrrolidine-1-carbonyl)thiomorpholine.
Loading…
