Sulfuric Acid → Methyl 5-hydroxy-2-methylbenzoate

HRID 1945272Notes

Reaction equation

HRID 1945272 reaction equation
S(=O)(=O)(O)O.N[C:7]1[CH:8]=[CH:9][C:10]([CH3:17])=[C:11]([CH:16]=1)[C:12]([O:14][CH3:15])=[O:13].N([O-])=[O:19].[Na+]>O>[OH:19][C:7]1[CH:8]=[CH:9][C:10]([CH3:17])=[C:11]([CH:16]=1)[C:12]([O:14][CH3:15])=[O:13]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 15049977Methyl 5-Amino-2-methylbenzoateHCID 23668193Sodium Nitrite

Product 1

HCID 13929055Methyl 5-hydroxy-2-methylbenzoate

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

A 0° C. solution of sulfuric acid (89 g, 908 mmol) in water (700 mL) was added to a flask containing methyl 5-amino-2-methylbenzoate (50 g, 303 mmol) in an ice-water bath. The resulting mixture was stirred until the mixture become a cloudy solution. A solution of sodium nitrite (21 g, 303 mmol) in cold water (200 mL) was added dropwise and stirring was continued for 1 h at 0° C. then at 100° C. for another 1 h. The reaction was cooled and the solid collected by filtration, and rinsed with water. The resultant dark red solid was re-dissolved in MeOH (500 mL). Charcoal (2 g) was added and the reaction was heated at reflux for 1 h. The mixture was filtered and concentrated. Chromatography over silica eluting with 0-50% EtOAc/hexane afforded the title compound as white solid. LC-MS: calculated for C9H10O3 166.17, observed m/e: no ionization (Rt 0.89/2 min). NMR (CDCl3): 7.48 (1H, s), 7.15 (1H, d); 6.95 (1H, d), 6.04 (1H, s); 3.95 (3H, s); 2.53 (3H, s).

Workup

  1. stirringstirring
  2. waitat 100° C. for another 1 h
  3. temperatureThe reaction was cooled
  4. filtrationthe solid collected by filtration
  5. washrinsed with water
  6. dissolutionThe resultant dark red solid was re-dissolved in MeOH (500 mL)
  7. additionCharcoal (2 g) was added
  8. temperaturethe reaction was heated
  9. temperatureat reflux for 1 h
  10. filtrationThe mixture was filtered
  11. concentrationconcentrated

Sources & evidence

ORD record
ord-4ce4c5cf354145699352349e27040d88
Source dataset
uspto-grants-2013_03
Patent number
US08394969B2

Reaction notes

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