Benzyl chloroformate → Tert-butyl 6-benzyloxycarbonylamino-3-bromo-2-(4-methylbenzenesulfonyloxy)benzoate

HRID 715981Notes

Reaction equation

HRID 715981 reaction equation
Cl[C:2]([O:4][CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=[O:3].[NH2:12][C:13]1[C:18]([C:19]([O:21][C:22]([CH3:25])([CH3:24])[CH3:23])=[O:20])=[C:17]([O:26][S:27]([C:30]2[CH:35]=[CH:34][C:33]([CH3:36])=[CH:32][CH:31]=2)(=[O:29])=[O:28])[C:16]([Br:37])=[CH:15][CH:14]=1>N1C=CC=CC=1>[CH2:5]([O:4][C:2]([NH:12][C:13]1[C:18]([C:19]([O:21][C:22]([CH3:24])([CH3:25])[CH3:23])=[O:20])=[C:17]([O:26][S:27]([C:30]2[CH:31]=[CH:32][C:33]([CH3:36])=[CH:34][CH:35]=2)(=[O:29])=[O:28])[C:16]([Br:37])=[CH:15][CH:14]=1)=[O:3])[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1

Participants

4

Reactant 2

HCID 10387Benzyl chloroformate3×HCID 86712121Tert-butyl 6-amino-3-bromo-2-(4-methylbenzenesulfonyloxy)benzoate2×

Product 1

HCID 86712120Tert-butyl 6-benzyloxycarbonylamino-3-bromo-2-(4-methylbenzenesulfonyloxy)benzoateYield 99.1%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

Benzyl chloroformate (1.705 g) was added to a stirred solution of tert-butyl 6-amino-3-bromo-2-(4-methylbenzensulfonyloxy)-benzoate (Intermediate 50, 3.8 g) in pyridine (50 mL) with cooling in ice. The mixture was stirred for 1 hour and further benzyl chloroformate (1.70 g) was added. The mixture was stirred for a further 1 hour and further benzyl chloroformate (1.70 g) was added. After stirring for a further 30 minutes, the solution was concentrated in vacuo and the residue was dissolved in DCM and 1M hydrochloric acid and filtered through a phase separator. The filtrate was concentrated in vacuo and the residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and cyclohexane with a gradient of 0-15% to give tert-butyl 6-benzyloxycarbonylamino-3-bromo-2-(4-methylbenzenesulfonyloxyl)benzoate (4.91 g) as a white solid.

Workup

  1. temperaturewith cooling in ice
  2. stirringThe mixture was stirred for a further 1 hour
  3. stirringAfter stirring for a further 30 minutes
  4. concentrationthe solution was concentrated in vacuo
  5. dissolutionthe residue was dissolved in DCM
  6. filtration1M hydrochloric acid and filtered through a phase separator
  7. concentrationThe filtrate was concentrated in vacuo
  8. customthe residue was purified by chromatography on silica
  9. washeluting with a mixture of ethyl acetate and cyclohexane with a gradient of 0-15%

Sources & evidence

ORD record
ord-60f0649846d344278f2120861ed9282d
Source dataset
uspto-grants-2015_11
Patent number
US09187494B2

Reaction notes

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