Dichloromethane → 1-(2-Nitrobenzenesulfonyl)-piperazin-2-one HCl salt
Reaction equation
C(OC([N:8]([CH2:13][CH2:14][NH:15][S:16]([C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][C:20]=1[N+:25]([O-:27])=[O:26])(=[O:18])=[O:17])[CH2:9][C:10](O)=[O:11])=O)(C)(C)C.C1(N=C=NC2CCCCC2)CCCCC1.[Cl:43]CCl>>[ClH:43].[N+:25]([C:20]1[CH:21]=[CH:22][CH:23]=[CH:24][C:19]=1[S:16]([N:15]1[CH2:14][CH2:13][NH:8][CH2:9][C:10]1=[O:11])(=[O:18])=[O:17])([O-:27])=[O:26]Participants
Procedure
To a solution of N-(t-butoxycarbonyl)-N-[2-(2-nitro-benzenesulfonylamino)-ethyl]-glycine (8.06 g, 20 mmol) in dichloromethane (100 ml) was added dicyclohexyl carbodiimide (5.16 g, 25 mmol). After stirring for 2 hours at room temperature, the precipitate was removed by filtration. The filtrate was concentrated and the residue was dissolved in ethyl actate (50 mL) and cooled to 0° C. The precipitate solid was removed and to the filtrate was added 2N-HCl in ethyl acetate (100 mL). The mixture was stirred for additional 10 h at ambient temperature. The precipitate product was filtered off, washed with ethyl acetate (500 mL), and dried in vacuo to afford the title compound as a white solid 5.39 g (79%). 1H-NMR (500 MHz; DMSO-d6) δ 9.95 (br.s, 2H), 8.38 (d, 1H), 8.04˜7.95 (m, 2H), 4.09 (dd, 2H), 3.96 (s, 2H), 3.56 (dd, 2H).
Workup
- customthe precipitate was removed by filtration
- concentrationThe filtrate was concentrated
- dissolutionthe residue was dissolved in ethyl actate (50 mL)
- temperaturecooled to 0° C
- customThe precipitate solid was removed and to the filtrate
- additionwas added 2N-HCl in ethyl acetate (100 mL)
- stirringThe mixture was stirred for additional 10 h at ambient temperature
- filtrationThe precipitate product was filtered off
- washwashed with ethyl acetate (500 mL)
- customdried in vacuo
Sources & evidence
- ORD record
- ord-c5f009b54d414613a7fc9ff686118464
- Source dataset
- uspto-grants-2006_04
- Patent number
- US07022851B2
Reaction notes
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