Sodium Bicarbonate → (S)-2-(2-Bromo-6-methyl-4-nitrophenyl)-2-tert-butoxyethyl pivalate

HRID 879271Notes

Reaction equation

[C:1]([O:7][CH2:8][C@H:9]([C:11]1[C:16]([CH3:17])=[CH:15][C:14]([N+:18]([O-:20])=[O:19])=[CH:13][C:12]=1[Br:21])[OH:10])(=[O:6])[C:2]([CH3:5])([CH3:4])[CH3:3].C([O-])(O)=O.[Na+]>C(OC(C)=O)(C)(C)C>[C:1]([O:7][CH2:8][C@H:9]([C:11]1[C:16]([CH3:17])=[CH:15][C:14]([N+:18]([O-:20])=[O:19])=[CH:13][C:12]=1[Br:21])[O:10][C:2]([CH3:4])([CH3:3])[CH3:1])(=[O:6])[C:2]([CH3:5])([CH3:4])[CH3:3]

Participants

Conditions

Temperature: 0 °C

Procedure

To a solution of (S)-2-(2-Bromo-6-methyl-4-nitrophenyl)-2-hydroxyethyl pivalate (13 g, 0.036 mol) in t-BuOAc (300 mL) at 0° C. was added HClO4 (20.7 g, 0.144 mol) slowly. The solution was stirred at 0° C. for 5 min, then warmed to room temperature and stirred at this temperature for 1.5 h. The solution was alkalized by saturated aqueous NaHCO3 until the pH of solution >8. The mixture was extracted with EtOAc (3×1 L). The combined organic layers were dried over anhydrous Na2SO4, filtered, concentrated in vacuo, and purified by silica gel column (Petroleum Ether:EtOAc (50:1)) to afford (S)-2-(2-Bromo-6-methyl-4-nitrophenyl)-2-tert-butoxyethyl pivalate (9.3 g, 62%) as yellow solid. 1H-NMR: 400 MHz, (CDCl3) δ: 8.26 (s, 1H), 7.98 (s, 1H), 5.60-5.57 (m, 1H), 4.32-4.27 (m, 1H), 4.18-4.14 (m, 1H), 2.73 (s, 3H), 1.17 (s, 9H), 1.14 (s, 9H).

Workup

temperaturewarmed to room temperature
stirringstirred at this temperature for 1.5 h
extractionThe mixture was extracted with EtOAc (3×1 L)
dry with materialThe combined organic layers were dried over anhydrous Na2SO4
filtrationfiltered
concentrationconcentrated in vacuo
custompurified by silica gel column (Petroleum Ether:EtOAc (50:1))

Sources & evidence

ORD record: ord-d951fbb90fb4437b8b371b21f368d302
Source dataset: uspto-grants-2015_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08987250B2

Reaction notes

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