4-Nitrobenzenesulfonyl chloride → (S)-3-{(R)-2-[4-(3,4-Dichloro-benzyloxy)-phenyl]-2,3-dihydro-benzo[1,4]dioxin-6-yl}-2-(4-nitro-benzenesulfonylamino)-propionic acid methyl ester
Reaction equation
Cl.[CH3:2][O:3][C:4](=[O:34])[C@@H:5]([NH2:33])[CH2:6][C:7]1[CH:32]=[CH:31][C:10]2[O:11][C@H:12]([C:15]3[CH:20]=[CH:19][C:18]([O:21][CH2:22][C:23]4[CH:28]=[CH:27][C:26]([Cl:29])=[C:25]([Cl:30])[CH:24]=4)=[CH:17][CH:16]=3)[CH2:13][O:14][C:9]=2[CH:8]=1.C([O-])(O)=O.[Na+].[N+:40]([C:43]1[CH:48]=[CH:47][C:46]([S:49](Cl)(=[O:51])=[O:50])=[CH:45][CH:44]=1)([O-:42])=[O:41]>CCOC(C)=O>[CH3:2][O:3][C:4](=[O:34])[C@@H:5]([NH:33][S:49]([C:46]1[CH:45]=[CH:44][C:43]([N+:40]([O-:42])=[O:41])=[CH:48][CH:47]=1)(=[O:50])=[O:51])[CH2:6][C:7]1[CH:32]=[CH:31][C:10]2[O:11][C@H:12]([C:15]3[CH:20]=[CH:19][C:18]([O:21][CH2:22][C:23]4[CH:28]=[CH:27][C:26]([Cl:29])=[C:25]([Cl:30])[CH:24]=4)=[CH:17][CH:16]=3)[CH2:13][O:14][C:9]=2[CH:8]=1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
(S)-2-Amino-3-{(R)-2-[4-(3,4-dichloro-benzyloxy)-phenyl]-2,3-dihydro-benzo[1,4]dioxin-6-yl}-propionic acid methyl ester hydrochloride (1.2 g) was dissolved in 100 mL EtOAc and 100 mL saturated aqueous NaHCO3 and 1.0 g p-nitrobenzenesulfonyl chloride was added. After stirring at room temperature for 2 hours, the layers were separated and the organic layer was dried over Na2SO4 and evaporated. The residue was purified by silica gel flash chromatography (hexanes to 7:3 hexanes/EtOAc) to give 1.7 g desired product after drying. 1H NMR (400 MHz, 8.27 (m, 2H), 7.89 (m, 2H), 7.54 (d, 1H), 7.45 (d, 1H), 7.35 (m, 2H), 7.28-7.24 (m, 1H), 7.20 (m, 2H), 6.81 (m, 1H), 6.56 (m, 2H) 5.26 (m, 1H), 5.02 (s, 2H), 4.99 (m, 1H), 4.26 (m, 2H), 3.95 (m, 1H), 3.66 (s, 3H), 3.05-2.85 (m, 2H).
Workup
- customthe layers were separated
- dry with materialthe organic layer was dried over Na2SO4
- customevaporated
- customThe residue was purified by silica gel flash chromatography (hexanes to 7:3 hexanes/EtOAc)
Sources & evidence
- ORD record
- ord-fb3fcda58b14459b9931b6c1cd1ea6ca
- Source dataset
- uspto-grants-2015_11
- Patent number
- US09175003B2
Reaction notes
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