Sulfuric Acid → Salicylic Acid

HRID 571576Notes

Reaction equation

HRID 571576 reaction equation
[OH:1][C:2]1[CH:10]=[CH:9][C:8](O)=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].S(=O)(=O)(O)O.C(O)(C)(C)C>CO>[C:4]([OH:6])(=[O:5])[C:3]1[C:2](=[CH:10][CH:9]=[CH:8][CH:7]=1)[OH:1]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 34692,5-Dihydroxybenzoic acidHCID 6386tert-Butanol2×

Product 1

HCID 338Salicylic AcidYield 83.6%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
50 °C

Procedure

While 100 g of 2,5-dihydroxybenzoic acid and 1441 g of 80% sulfuric acid are heated to 50° C., these are mixed. 144 g of tert-butyl alcohol is added to the mixed solution, and stirred at 50° C. for 30 minutes. Next, the operation is performed 3 times in which 144 g of tert-butyl alcohol is added to the mixed solution, and stirred at 50° C. for 30 minutes. The reaction solution is cooled to room temperature. The reaction solution is gradually poured into 1.00 kg of ice water, and a precipitate is filtered. The precipitate is washed with water, and further washed with hexane. The precipitate obtained here is dissolved in 200 mL of methanol, and again precipitated using 3.60 L of water. After filtration, the obtained product is dried at 80° C. to obtain 74.9 g of a salicylic acid intermediate product represented by the following formula (8).

Workup

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

Sources & evidence

ORD record
ord-d6a09d38e04143d9babe0e220e4875da
Source dataset
uspto-grants-2015_05
Patent number
US09029056B2

Reaction notes

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