p-Bromobenzenesulfonyl chloride → 2-(4-Bromo-benzenesulfonylamino)-3-methyl-butyric acid methyl ester

HRID 915756Notes

Reaction equation

[Br:1][C:2]1[CH:7]=[CH:6][C:5]([S:8](Cl)(=[O:10])=[O:9])=[CH:4][CH:3]=1.[NH2:12][C@@H:13]([C:17]([O:19][CH3:20])=[O:18])[CH:14]([CH3:16])[CH3:15].CCN(C(C)C)C(C)C>ClCCl>[CH3:20][O:19][C:17](=[O:18])[CH:13]([NH:12][S:8]([C:5]1[CH:6]=[CH:7][C:2]([Br:1])=[CH:3][CH:4]=1)(=[O:10])=[O:9])[CH:14]([CH3:16])[CH3:15]

Participants

Conditions

Temperature: 0 °C

Procedure

Step 1A [Intermediate 1] To a dry round-bottom flask was added 4-Bromo-benzenesulfonyl chloride (12.2 g, 47.7 mmol, 1 equiv.), anhydrous methylene chloride (170 mL), and H-D-Val-OMe (8.0 g, 47.7 mmol, 1 equiv.). The mixture was cooled to 0° C. in an ice bath followed by the addition of Hunig base (19.11 mL, 109.7 mmol, 2.3 equiv.). The reaction mixture was allowed to warm to room temperature and was stirred overnight. Reaction was complete as determined by TLC. The reaction mixture was then diluted with dichloromethane (100 mL) and washed with brine. The organic layer was dried over anhydrous MgSO4, solvent evaporated to yield 2-(4-Bromo-benzenesulfonylamino)-3-methyl-butyric acid methyl ester in 96% yield (16.0 g). 1H NMR (400 MHz, CHLOROFORM-D) δ ppm 0.87 (d, J=6.82 Hz, 3 H) 0.96 (d, J=6.82 Hz, 3 H) 2.04 (m, 1 H) 3.49 (s, 3 H) 3.74 (d, J=14.40 Hz, 1 H) 5.10 (d, J=9.85 Hz, 1 H) 7.66 (m, 4 H).

Workup

temperatureto warm to room temperature
customReaction
washwashed with brine
dry with materialThe organic layer was dried over anhydrous MgSO4, solvent
customevaporated

Sources & evidence

ORD record: ord-cc243fa5d78c4386bc346b8a36849a53
Source dataset: uspto-grants-2007_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07268135B2

Reaction notes

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