O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate → 2-{[(2R)-2-Amino-2-(4-hydroxyphenyl)acetyl]amino}ethane-1-sulfonic acid
Reaction equation
C(N([C:13]1[CH:18]=[CH:17][C:16]([OH:19])=[CH:15][CH:14]=1)CC(O)=O)(OC(C)(C)C)=O.[NH2:20][CH2:21][CH2:22][S:23]([OH:26])(=[O:25])=[O:24].[CH2:27]([N+:31](CCCC)(CCCC)CCCC)[CH2:28]CC.CN(C([O:51]N1N=NC2C=CC=CC1=2)=[N+](C)C)C.[B-](F)(F)(F)F>CN(C=O)C>[NH2:31][C@H:27]([C:13]1[CH:14]=[CH:15][C:16]([OH:19])=[CH:17][CH:18]=1)[C:28]([NH:20][CH2:21][CH2:22][S:23]([OH:26])(=[O:25])=[O:24])=[O:51]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
N-Boc-4-hydroxyphenylglycine (1.00 g, 3.21 mmol) was dissolved in DMF (5 ml) and tetrabutylammonium taurine (2.36 g, 6.42 mmol) was added together with additionally 5 ml DMF. The resulting suspension was cooled on ice and TBTU (1.24 g, 3.85 mmol) was added. The ice bath was removed after 30 min and the mixture was stirred for 2 hours before it was filtered and concentrated. TFA in DCM (20%, 20 ml) was added and the reaction mixture was stirred over night. Ethanol (20 ml) was added and the solvents evaporated. The crude product was refluxed in ethanol (100 ml) for 1 hour. Filtration yielded the pure title compound as a white solid, 626 mg (71%). NMR DMSO-d6): 2.4–2.6 (m, 2H),3.2–3.4 (m, 2H),4.79 (s, 1H), 6.78 (d, 2H), 7.23 (d, 2H), 8.22 (t, 1H), 8.4 (brs, 3H), 9.7 (s, 1H).
Workup
- additionwas added
- customThe ice bath was removed after 30 min
- filtrationwas filtered
- concentrationconcentrated
- additionTFA in DCM (20%, 20 ml) was added
- stirringthe reaction mixture was stirred over night
- additionEthanol (20 ml) was added
- customthe solvents evaporated
- temperatureThe crude product was refluxed in ethanol (100 ml) for 1 hour
- filtrationFiltration
Sources & evidence
- ORD record
- ord-dd0441e2f89c4612b064616c35b4eae4
- Source dataset
- uspto-grants-2007_06
- Patent number
- US07226943B2
Reaction notes
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