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

HRID 133403Notes

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-b38c9367e15a49778017cd0976833565
Source dataset: uspto-grants-2008_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07390833B2

Reaction notes

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