Sulfuric Acid → 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, the solution which had been subjected to the hydrolysis was passed through a 2.5-cm-diameter, 2.5-cm-high column packed with 25 g of powdery active carbon (Taiko Active Carbon SGA). The thus treated 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 86.1 g of cinnamic acid. The purity of cinnamic acid was 98.6%, and the content of each of palladium, copper and manganese was 5 ppm or less. 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. customThe thus treated solution was placed in a 2-liter flask
4. customequipped with a thermometer and a stirrer
5. temperaturemaintained at 40° C.
6. customto precipitate the crystals of cinnamic acid
7. additionAfter the addition of sulfuric acid
8. customwas lowered to 20° C.
9. filtrationby filtering through Nutsche
10. filtrationThe resultant filter cake
11. washwas washed with 1000 g of water
12. customvacuum-dried at 50° C.

ORD record

ord-58ed6717a9874ed1ba724f93cf326101

Source dataset

uspto-grants-1993_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05206430