反应详情

温度

180 °C

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.

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®