Hydrochloric Acid → 3-Bromo-5-methoxybenzoic acid

HRID 662034Notes

Reaction equation

HRID 662034 reaction equation
N[C:2]1[C:10]([O:11][CH3:12])=[CH:9][C:8]([Br:13])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].Cl.N([O-])=O.[Na+].O[PH2]=O>O.C1COCC1>[Br:13][C:8]1[CH:7]=[C:3]([CH:2]=[C:10]([O:11][CH3:12])[CH:9]=1)[C:4]([OH:6])=[O:5]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 4124402Phosphinic AcidHCID 23668193Sodium NitriteHCID 454804572-Amino-5-bromo-3-methoxybenzoic acid

Product 1

HCID 40600483-Bromo-5-methoxybenzoic acidYield 62.3%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 2-amino-5-bromo-3-(methyloxy)benzoic acid (16.40 g, 66.65 mmol) in H2O (80 mL), was added conc. HCl (30 mL) and THF (5 mL) at 0° C. The reaction mixture was stirred for 30 min, and then NaNO2 (14.00 g, 202.91 mmol) was cautiously added to the solution. This solution was stirred for 2 h, and then H3PO2 (22.00 g, 333.35 mmol) was cautiously added to the solution. The solution was kept stirring overnight at the room temperature (monitored by TLC), then filtered and rinsed with water (50 mL×2). The resulting solid was dried to afford 3-bromo-5-(methyloxy)benzoic acid (9.60 g, 62%). 1H NMR (400 MHz, CDCl3) δ 7.46 (t, J=1.6 Hz, 1H), 7.31 (q, J=16.8 Hz, 1H), 7.21 (t, J=16.8 Hz, 1H), 3.84 (s, 1H).

Workup

  1. stirringThis solution was stirred for 2 h
  2. stirringThe solution was kept stirring overnight at the room temperature (monitored by TLC)
  3. filtrationfiltered
  4. washrinsed with water (50 mL×2)
  5. customThe resulting solid was dried

Sources & evidence

ORD record
ord-8af1530df1ae4f5ab1e8c87ca099b6c4
Source dataset
uspto-grants-2011_12
Patent number
US08084449B2

Reaction notes

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