Sulfuric Acid → Salicylic Acid

Temperature

50 °C

While 100 g of 2,5-dihydroxybenzoic acid and 1441 g of 80% sulfuric acid were heated to 50° C., these were mixed. 144 g of tert-butyl alcohol was added to the mixed solution, and stirred at 50° C. for 30 minutes. Next, the operation was performed 3 times in which 144 g of tert-butyl alcohol was added to the mixed solution, and stirred at 50° C. for 30 minutes. The reaction solution was cooled to room temperature. The reaction solution was gradually poured into 1.00 kg of ice water, and a precipitate was filtered. The precipitate was washed with water, and further washed with hexane. The precipitate obtained here was dissolved in 200 mL of methanol, and again precipitated in 3.60 L of water. After filtration, the obtained product was dried at 80° C. to obtain 74.9 g of a salicylic acid intermediate product represented by the following formula (7).

1. additionthese were mixed
2. additionwas added to the mixed solution
3. stirringstirred at 50° C. for 30 minutes
4. temperatureThe reaction solution was cooled to room temperature
5. filtrationa precipitate was filtered
6. washThe precipitate was washed with water
7. washfurther washed with hexane
8. customThe precipitate obtained here
9. customagain precipitated in 3.60 L of water
10. filtrationAfter filtration
11. customthe obtained product was dried at 80° C.

ORD record

ord-d85d691887ae4bc283d79abb764ddfa0

Source dataset

uspto-grants-2015_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09098002B2