2,4-Dimethoxybenzoic acid → 5-Bromo-2,4-dimethoxybenzoic acid

HRID 555131

Reaction equation

HRID 555131 reaction equation
[CH3:1][O:2][C:3]1[CH:11]=[C:10]([O:12][CH3:13])[CH:9]=[CH:8][C:4]=1[C:5]([OH:7])=[O:6].[Br:14]Br>C(Cl)(Cl)Cl>[Br:14][C:9]1[C:10]([O:12][CH3:13])=[CH:11][C:3]([O:2][CH3:1])=[C:4]([CH:8]=1)[C:5]([OH:7])=[O:6]

Participants

4

Reactant 2

HCID 70522,4-Dimethoxybenzoic acidHCID 24408Bromine

Product 1

HCID 135050975-Bromo-2,4-dimethoxybenzoic acidYield 78.3%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Conditions

Temperature
0 °C

Procedure

To a 250 mL round-bottomed flask was added chloroform (60 mL) along with 2,4-dimethoxybenzoic acid (2.0 g, 10.98 mmol). The solution was cooled to 0° C. and bromine (0.566 mL, 10.98 mmol) was added dropwise over 5 minutes. The solution was allowed to warm to room temperature and stirred overnight. The resulting solid was filtered, washed with cold chloroform and dried under vacuum to give 2.49 g (8.6 mmol, 78% yield) of 5-bromo-2,4-dimethoxybenzoic acid as a yellow solid. The LC/MS data was obtained on a Shimadzu analytical LC/MICROMASS® Platform LC (ESI+) at 220 nm using the following set of conditions: PHENOMENEX® Luna 3 μm C18, 2×30 mm column, with a gradient of 0-100% B (B=90% HPLC grade acetonitrile/0.1% trifluoroacetic acid/10% HPLC grade water), (A=90% HPLC grade water/0.1% trifluoroacetic acid/10% HPLC grade acetonitrile), in 2 minutes with a 1 minute hold at a rate of 1.0 mL/minute. 1H NMR (400 MHz, DMSO-d6) δ ppm 3.88 (s, 3H), 3.95 (s, 3H), 6.78 (s, 1H), 7.86 (s, 1H). LCMS Rt=1.453 min., m/z 262.99 (M+H), 93% purity.

Workup

  1. temperatureto warm to room temperature
  2. filtrationThe resulting solid was filtered
  3. washwashed with cold chloroform
  4. customdried under vacuum

Sources & evidence

ORD record
ord-e9e117610ed848909f94ed936d3ad571
Source dataset
uspto-grants-2011_11
Patent number
US08048887B2

Linked notes

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