Reaction #725874

Reaction equation

benzoic acid

benzoic acid

2-phenylethyl alcohol

→

2-phenylethyl benzoate

Yield 88.4%

Conditions

Workup

1. 1
   TemperatureThe system was heated gently
2. 2
   workup.DISSOLUTIONdissolved
3. 3
   OtherThe air was removed with three cycles of evacuation/nitrogen
4. 4
   Temperaturewas increased to ca. 200 rpm
5. 5
   Otherthe nitrogen sparge
6. 6
   TemperatureAfter a 1-h hold, the temperature was increased to 150° C
7. 7
   TemperatureThe temperature was increased to 160° C.
8. 8
   Otherthe nitrogen sparge
9. 9
   Temperaturewas increased to 0.5 scfh
10. 10
    TemperatureAfter a 1-h hold, the reaction mixture was cooled to room temperature
11. 11
    workup.ALIQUOTsampled for analysis
12. 12
    workup.ADDITIONTo the reaction mixture at 25° C. was added 213 g of 10% w/w aqueous sodium carbonate solution
13. 13
    TemperatureThe batch was heated to 50° C.
14. 14
    workup.STIRRINGstirred for 15 min
15. 15
    workup.WAITto settle for 30 min
16. 16
    OtherThe bottom aqueous layer was removed from the flask with a pipette, and 2-phenylethyl alcohol
17. 17
    Otherwas removed by vacuum distillation at 180-190° C. (20 torr) for 1 h with a nitrogen sweep of 0.5 scfh
18. 18
    TemperatureThe reaction mixture was cooled to ca. 70° C.
19. 19
    workup.ALIQUOTsampled for analysis
20. 20
    FiltrationTreatment with activated carbon and filtration as usual (see Example 1)

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, 5.30 g (0.43% w/w, 1.0 mol %) of methanesulfonic acid (MSA) and 1.25 g (0.1% w/w) of triisodecylphosphite (TDP). 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 140° C. After a 1-h hold, the temperature was increased to 150° C, and held for 1 h. The temperature was increased to 160° C. and the nitrogen sparge was increased to 0.5 scfh. After a 1-h hold, the reaction mixture was cooled to room temperature and sampled for analysis. The acid number was 8.1 mg KOH/g (97.3% conversion of benzoic acid, corrected for MSA), the APHA color was 66, and the excess 2-phenylethyl alcohol was 7.9% by GLC. To the reaction mixture at 25° C. was added 213 g of 10% w/w aqueous sodium carbonate solution. The batch was heated to 50° C. and stirred for 15 min. The stirring was stopped and the batch was allowed to settle for 30 min. The bottom aqueous layer was removed from the flask with a pipette, and 2-phenylethyl alcohol was removed by vacuum distillation at 180-190° C. (20 torr) for 1 h with a nitrogen sweep of 0.5 scfh. The reaction mixture was cooled to ca. 70° C. and sampled for analysis. The residual 2-phenylethyl alcohol was 0.17% by GLC, the acid number was 0.10 mg KOH/g, and the APHA color was 95. Treatment with activated carbon and filtration as usual (see Example 1) gave 1100 g (88%) of 2-phenylethyl benzoate. The APHA color was 72, the acid number was 0.11 mg KOH/g, the saponification number was 242 mg KOH/g, the residual sulfur was <10 ppm, and the residual phosphorous was <10 ppm.

Source