2-Propenoic acid, 3-phenyl-, methyl ester → 2-Propenoic acid, 3-phenyl-

Temperature

80 °C

100 g of crude methyl cinnamate and 926.8 g of 2.8% caustic soda were placed in a 2-liter flask equipped with a thermometer and a stirrer, and the solution was then stirred at 80° C. for 30 minutes to carry out hydrolysis. Furthermore, 1 g of powdery active carbon (trade name PMSX, made by Toyo Calgon Inc.) was added, and the solution was stirred for 30 minutes and then filtered at 80° C. by the use of Nutsche. Next, 100 g of toluene was added to the resultant filtrate, and the solution was then stirred at 80° C. for 30 minutes, and after the stop of the stirring, the solution was allowed to stand and separate and the resultant toluene layer was then removed. The resultant aqueous solution was placed in a 2-liter flask equipped with a thermometer and a stirrer and then maintained at 40° C., and 137.1 g of 25% sulfuric acid was added dropwise to precipitate the crystals of cinnamic acid. After the addition of sulfuric acid had been over, the temperature of the solution was lowered to 20° C., followed by filtering through Nutsche. The resultant filter cake was washed with 1000 g of water, and then vacuum-dried at 50° C. to obtain 85.4 g of cinnamic acid. The purity of cinnamic acid was 99.9%, and the content of each of palladium, copper and manganese was 5 ppm or less. The recovered active carbon was dried, and metallic components were then measured. As a result, the contents of palladium, copper and manganese were 880 ppm, 8.6 ppm and 5.8%, respectively. In the filtrate and the washing solution with which cinnamic acid had been washed, metallic components of palladium, copper and manganese were each contained in an amount of 5 ppm or less.

1. customequipped with a thermometer and a stirrer
2. customhydrolysis
3. additionFurthermore, 1 g of powdery active carbon (trade name PMSX, made by Toyo Calgon Inc.) was added
4. stirringthe solution was stirred for 30 minutes
5. filtrationfiltered at 80° C. by the use of Nutsche
6. additionNext, 100 g of toluene was added to the resultant filtrate
7. stirringthe solution was then stirred at 80° C. for 30 minutes
8. customseparate
9. customthe resultant toluene layer was then removed
10. customThe resultant aqueous solution was placed in a 2-liter flask
11. customequipped with a thermometer and a stirrer
12. temperaturemaintained at 40° C.
13. addition137.1 g of 25% sulfuric acid was added dropwise
14. customto precipitate the crystals of cinnamic acid
15. additionAfter the addition of sulfuric acid
16. customwas lowered to 20° C.
17. filtrationby filtering through Nutsche
18. filtrationThe resultant filter cake
19. washwas washed with 1000 g of water
20. customvacuum-dried at 50° C.

ORD record

ord-ae467b435576420fa267bf70aacc0dba

Source dataset

uspto-grants-1993_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05206430