Sulfuric Acid → Methyl 4-hydroxy-2-methoxybenzoate

HRID 1025163Notes

Reaction equation

HRID 1025163 reaction equation
N[C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[C:4]([O:12][CH3:13])[CH:3]=1.S(=O)(=O)(O)[OH:15].N([O-])=O.[Na+]>C(Cl)Cl>[OH:15][C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[C:4]([O:12][CH3:13])[CH:3]=1

Participants

5

Reactant 3

HCID 1118Sulfuric Acid2×HCID 168705Methyl 4-amino-o-anisateHCID 23668193Sodium Nitrite

Product 1

HCID 12532676Methyl 4-hydroxy-2-methoxybenzoateYield 75.7%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

To a 250 mL Erlenmeyer flask was added methyl 4-amino-2-methoxybenzoate (7.5 g, 41.4 mmol) and a 25% solution of sulfuric acid (40 mL, 188 mmol). The solution was cooled to 0° C. and a saturated solution of sodium nitrite (4.29 g, 62.2 mmol) was added drop wise. The orange mixture was stirred for 15 minutes. The resulting diazonium solution was then very slowly poured into a 1 L flask containing 500 mL of 3% sulfuric acid. The solution was stirred for 5 minutes then transferred to a separatory funnel. The reaction mixture was diluted with 150 mL of DCM, extracted, dried over magnesium sulfate and concentrated. to a red solid. The resulting solid was triturated with hexane to give 5.71 grams of the desired phenol as a red powder (73% yield). The LC/MS data was obtained on a Shimadzu analytical LC/Micromass Platform LC (ESI+) at 220 nm using the following set of conditions: Waters Sunfire 5 μm C18, 4.6×30 mm column, with a gradient of 0-100% B (B=90% HPLC grade methanol/0.1% trifluoroacetic acid/10% HPLC grade water), (A=90% HPLC grade water/0.1% trifluoroacetic acid/10% HPLC grade methanol), in 2 minutes with a 1 minute hold at a rate of 4 mL/minute. 1H NMR (400 MHz, DMSO-d6) δ ppm 3.67-3.72 (m, 3 H), 3.74 (s, 3 H), 6.39 (dd, J=8.66, 2.13 Hz, 1 H), 6.45 (d, J=2.13 Hz, 1 H), 7.59 (d, J=8.66 Hz, 2 H). LCMS Rt=1.070 min., m/z 183.09 (M+H), 96% purity.

Workup

  1. stirringThe solution was stirred for 5 minutes
  2. customthen transferred to a separatory funnel
  3. extractionextracted
  4. dry with materialdried over magnesium sulfate
  5. concentrationconcentrated
  6. customThe resulting solid was triturated with hexane

Sources & evidence

ORD record
ord-d7c5e76b8b594a1d8095d4db696cd976
Source dataset
uspto-grants-2014_05
Patent number
US08722688B2

Reaction notes

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