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. The resultant filtrate 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 86.0 g of cinnamic acid. The purity of cinnamic acid was 98.8%, 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 990 ppm, 8.5% and 5.7%, 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. customThe resultant filtrate was placed in a 2-liter flask
7. customequipped with a thermometer and a stirrer
8. temperaturemaintained at 40° C.
9. addition137.1 g of 25% sulfuric acid was added dropwise
10. customto precipitate the crystals of cinnamic acid
11. additionAfter the addition of sulfuric acid
12. customwas lowered to 20° C.
13. filtrationby filtering through Nutsche
14. filtrationThe resultant filter cake
15. washwas washed with 1000 g of water
16. customvacuum-dried at 50° C.

ORD record

ord-940b23267e1d487c9aa42f9b6044e938

Source dataset

uspto-grants-1993_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05206430