Hydrochloric Acid → 2,4-Bis(benzyloxy)-5-bromobenzoic acid

HRID 2079848Notes

Reaction equation

C([O:8][C:9](=[O:33])[C:10]1[CH:15]=[C:14]([Br:16])[C:13]([O:17][CH2:18][C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)=[CH:12][C:11]=1[O:25][CH2:26][C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1)C1C=CC=CC=1.[Li+].[OH-].Cl>O1CCCC1.O>[CH2:26]([O:25][C:11]1[CH:12]=[C:13]([O:17][CH2:18][C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[C:14]([Br:16])=[CH:15][C:10]=1[C:9]([OH:33])=[O:8])[C:27]1[CH:28]=[CH:29][CH:30]=[CH:31][CH:32]=1

Participants

Conditions

Temperature: 80 °C

Procedure

2,4-Bis-benzyloxy-5-bromo-benzoic acid benzyl ester (47.8 g, 95 mmol) was then dissolved in mixture of tetrahydrofuran (150 ml) and water (150 ml). LiOH (7.2 g, 0.3 mol) was added, and the resulting mixture was stirred at 80° C. overnight. After the reaction was complete, the reaction was cooled to r.t., acidified with 1M HCl to pH=1. After extraction with Et2O (500 ml×3), the combined organics were washed with water (250 ml) and saturated brine (250 ml) and dried over Na2SO4. After filtration and concentration, 2,4-bis-benzyloxy-5-bromobenzoic acid was obtained as a white solid (37.7 g, 96%). M.p.: 116-119° C.; 400 MHz 1H NMR (CDCl3) δ: 8.36 (s, 1H), 7.45-7.33 (m, 10H), 6.59 (s, 1H); 5.19 (s, 2H), 5.17 (s, 2H); LCMS: 413, 415 [M+H].

Workup

temperaturethe reaction was cooled to r.t.
extractionAfter extraction with Et2O (500 ml×3)
washthe combined organics were washed with water (250 ml) and saturated brine (250 ml)
dry with materialdried over Na2SO4
filtrationAfter filtration and concentration

Sources & evidence

ORD record: ord-b350004eb0ad49f59aaeae62fbf88196
Source dataset: uspto-grants-2011_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07932279B2

Reaction notes

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