Phosphinic Acid → 3-Bromo-5-methoxybenzoic acid

HRID 564452Notes

Reaction equation

HRID 564452 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].N([O-])=O.[Na+].O[PH2]=O>O.Cl.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 3

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

Product 1

HCID 40600483-Bromo-5-methoxybenzoic acidYield 62.3%

Reagents, catalysts & solvents 3

HCID 313Hydrochloric AcidSolventHCID 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), conc. HCl (30 mL) and THF (5 mL) were added at 0° C. The reaction was stirred for 30 min, and then NaNO2 (14.00 g, 202.91 mmol) was cautiously added to the solution. After the reaction mixture had stirred for 2 h, H3PO2 (22.00 g, 333.35 mmol) was cautiously added to the solution. The reaction was kept stirring overnight at the room temperature (monitored by TLC), and filtered and rinsed with water (50 mL×2). The formed precipitate 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, 1 H), 7.31 (q, J=16.8 Hz, 1 H), 7.21 (t, J=16.8 Hz, 1 H), 3.84 (s, 1 H).

Workup

  1. stirringAfter the reaction mixture had stirred for 2 h
  2. stirringThe reaction was kept stirring overnight at the room temperature (monitored by TLC)
  3. filtrationfiltered
  4. washrinsed with water (50 mL×2)
  5. customThe formed precipitate was dried

Sources & evidence

ORD record
ord-14e8dc6960fc4773b9a2e652e81ee854
Source dataset
uspto-grants-2011_11
Patent number
US08067408B2

Reaction notes

Loading…