4-Hydroxybenzoic Acid → 4-hydroxy-N-phenylbenzaMide

HRID 976932Notes

Reaction equation

HRID 976932 reaction equation
[OH:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=O)=[CH:4][CH:3]=1.[C:11]1([N:17]=C=O)[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1>[O-]CC.[Na+].O>[OH:1][C:2]1[CH:3]=[CH:4][C:5]([C:6]([NH:17][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=[O:8])=[CH:9][CH:10]=1

Participants

5

Reactant 2

HCID 1354-Hydroxybenzoic Acid2×HCID 7672Phenyl isocyanate

Product 1

HCID 5647164-hydroxy-N-phenylbenzaMide

Reagents, catalysts & solvents 2

HCID 2723922Sodium ethoxideCatalystHCID 962WaterSolvent

Conditions

Temperature
23 °C

Procedure

p-Hydroxybenzoic acid (96.68 grams, 0.70 mole), sodium ethoxide catalyst (0.218 gram, 0.225% wt. of the p-hydroxybenzoic acid used) and N,N'-dimethylacetamide solvent (550 grams) are added to a reactor equipped with a reflux condenser and stirred under a nitrogen atmosphere at 23° C. to provide a solution. Phenyl isocyanate (87.55 grams, 0.735 mole) is added inducing a maximum exoptherm of 46° C. four minutes later. Three minutes after the maximum exotherm temperature is achieved, heating of the reactor commences and a 160° C. reaction temperature is achieved 94 minutes later. After three hours at the 160° C. reaction temperature, the reactor is cooled to 50° C. then the contents poured into 4 liters of deionized water. A precipitated product is recovered via filtration of the aqueous slurry, washed with deionized water (500 milliliters) then dissolved into boiling methanol (850 milliliters) and refluxed therein (67° C.). After cooling the methanol solution to room temperature (23° C.) and maintaining therein for sixteen hours, a white crystalline product is filtered off, washed with methanol (100 milliliters) and dried in a vacuum oven at 80° C. and 1 mm Hg to a constant weight of 99.49 grams. Fourier transform infrared spectrophotometric analysis of a potassium bromide pellet of a portion of the product revealed the presence of the expected hydroxyl group O--H and secondary amide (solid state) N--H stretching at 3336 cm-1 (sharp) with a shoulder at 3409 cm-1 and the secondary amide carbonyl stretching (solid state) at 1656 cm-1 (sharp).

Workup

  1. additionare added to a reactor
  2. customequipped with a reflux condenser
  3. customto provide a solution
  4. customa maximum exoptherm of 46° C. four minutes
  5. customThree minutes
  6. temperatureheating of the reactor commences and a 160° C.
  7. customreaction temperature
  8. customAfter three hours at the 160° C. reaction temperature
  9. temperaturethe reactor is cooled to 50° C.
  10. filtrationA precipitated product is recovered via filtration of the aqueous slurry
  11. washwashed with deionized water (500 milliliters)
  12. dissolutionthen dissolved
  13. temperaturerefluxed
  14. custom(67° C.)
  15. temperatureAfter cooling the methanol solution to room temperature (23° C.)
  16. temperaturemaintaining
  17. waitfor sixteen hours
  18. filtrationa white crystalline product is filtered off
  19. washwashed with methanol (100 milliliters)
  20. customdried in a vacuum oven at 80° C.

Sources & evidence

ORD record
ord-ff3e0306858741fda3283bf478b0ad95
Source dataset
uspto-grants-1997_03
Patent number
US05612479

Reaction notes

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