Hydrochloric Acid → (4-Nitrophenyl)methyl (2S,4S)-2-[[(aminosulfonyl)amino]methyl]-4-mercapto-1-pyrrolidinecarboxylate

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Reaction Steps

To a solution of crude (2S,4S)-1-p-nitrobenzyloxycarbonyl-2-aminomethyl-4-mercaptopyrrolidine (3.3 g: 10.18 mmole) in dichloromethane (100 ml) at -78° C., triethylamine (2.84 ml: 2.2 eq.) and trimethylchlorosilane (3.12 ml: 2.2 eq.) are dropwise added. After stirring for 20 minutes, triethylamine (4.25 ml: 3 eq.) and 1M-sulfamoyl chloride in dichloromethane (25 ml: 2.5 eq.) are dropwise added to the mixture. After 20 minutes stirring, the reaction mixture is acidified with hydrochloric acid, warmed to room temperature, and extracted with dichloromethane. The extract is washed with water, and 1N-hydrochloric acid (10 ml) and methanol (30 ml) are added thereto. The solution is stirred at room temperature for 30 minutes. The reaction mixture is washed with water, dried over magnesium sulfate, and concentrated in vacuo. The residue is purified by silica gel column chromatography (toluene: ethyl acetate) to give (2S,4S)-1-p-nitrobenzyloxycarbonyl-2-sulfamoylaminomethyl-4-mercaptopyrrolidine (2.65 g). Yield: 66.7%. NMR δ(CDCl3 -CD3OD) ppm: 1.42(t, J=7 Hz, 1H), 1.65 to 1.93(m, 1H), 2.48 to 2.70(m, 1H), 3.05 to 3.63(m, 4H), 3.93 to 4.16(m, 2H), 5.22(s, 2H), 7.53(d, J=8 Hz, 2H), 8.23(d, J=8 Hz, 2H). IR ν (CHCl3) cm-1 : 3276br, 1692, 1607.

Provenance & Evidence