Benzoic Acid → Phenethyl Benzoate

HRID 638689Notes

Reaction equation

HRID 638689 reaction equation
[C:1]([OH:9])(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:10]1([CH2:16][CH2:17]O)[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1>>[C:1]([O:9][CH2:17][CH2:16][C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

3

Reactant 2

HCID 243Benzoic Acid2×HCID 60542-Phenylethanol

Product 1

HCID 7194Phenethyl BenzoateYield 90%

Conditions

Temperature
180 °C

Procedure

A 2-L, 4-neck round bottom flask, fitted with a thermometer, mechanical stirrer, nitrogen inlet tube and Liebig condenser/receiving flask, was charged with 671.7 g (5.50 mol, 1.00 equiv) of benzoic acid, 806.3 g (6.60 mol, 1.20 equiv) of 2-phenylethyl alcohol, and 1.25 g (0.1% w/w) of Fascat 2001®. The system was heated gently with slow stirring (<50 rpm) until the benzoic acid dissolved. The air was removed with three cycles of evacuation/nitrogen fill using a mechanical vacuum pump (50-100 torr). The rate of stirring was increased to ca. 200 rpm, the nitrogen sparge was set at 0.2 scfh, and the reaction mixture was heated to 180° C. After a 1-h hold, the temperature was increased to 190° C. for 1 h and then to 200° C. for 1 h. The temperature was increased to 210° C. and the nitrogen sparge was increased to 0.5 scfh. After a 1-h hold, the temperature was further increased to 220° C. for 1 h. The total amount of distillate was 159.2 g, from which 94.4 g of water (theor. 99.1 g) was separated as the top layer. The reaction mixture was cooled to room temperature and sampled for analysis. The acid number was 1.10 mg KOH/g (99.7% conversion) and the APHA color was 115. The excess 2-phenylethyl alcohol (5.5% by GLC) was removed by vacuum distillation. Thus, after 1 h at 180-190° C. and 20 torr (0.5 scfh nitrogen sweep), the residual 2-phenylethyl alcohol was <0.05% by GLC and the APHA color was 222. Activated carbon (37.3 g, 3% w/w) was added, and the mixture was heated at 75-80° C. under vacuum (50-70 torr) for 1 h. After cooling to room temperature, filtration through Celite® gave 1100 g (90%) of 2-phenylethyl benzoate. The APHA color was 20, the acid number was 0.14 mg KOH/g, the saponification number was 246 mg KOH/g (theor. 248), and the residual tin was <10 ppm.

Workup

  1. temperatureThe system was heated gently
  2. dissolutiondissolved
  3. customThe air was removed with three cycles of evacuation/nitrogen
  4. temperaturewas increased to ca. 200 rpm
  5. customthe nitrogen sparge
  6. temperatureAfter a 1-h hold, the temperature was increased to 190° C. for 1 h
  7. temperatureThe temperature was increased to 210° C.
  8. customthe nitrogen sparge
  9. temperaturewas increased to 0.5 scfh
  10. temperatureAfter a 1-h hold, the temperature was further increased to 220° C. for 1 h
  11. customfrom which 94.4 g of water (theor. 99.1 g) was separated as the top layer
  12. temperatureThe reaction mixture was cooled to room temperature
  13. aliquotsampled for analysis
  14. customThe excess 2-phenylethyl alcohol (5.5% by GLC) was removed by vacuum distillation
  15. waitThus, after 1 h at 180-190° C.
  16. additionActivated carbon (37.3 g, 3% w/w) was added
  17. temperaturethe mixture was heated at 75-80° C. under vacuum (50-70 torr) for 1 h
  18. temperatureAfter cooling to room temperature
  19. filtrationfiltration through Celite®

Sources & evidence

ORD record
ord-9a35a9a293284e53bd65a7cdfebdea1d
Source dataset
uspto-grants-2010_04
Patent number
US07691363B2

Reaction notes

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