Sodium Hydroxide → 3-Hydroxy-2-methylbenzoic Acid

HRID 1416079Notes

Reaction equation

HRID 1416079 reaction equation
C([O:8][C:9]1[C:10]([CH3:18])=[C:11]([CH:15]=[CH:16][CH:17]=1)[C:12]([OH:14])=[O:13])C1C=CC=CC=1.[OH-].[Na+].[H][H]>O.[Pd]>[OH:8][C:9]1[C:10]([CH3:18])=[C:11]([CH:15]=[CH:16][CH:17]=1)[C:12]([OH:14])=[O:13]

Participants

6

Reactant 3

HCID 14798Sodium HydroxideHCID 118068023-Benzyloxy-2-methyl-benzoic acidHCID 178418361HCID 178418361, compound2×

Product 1

HCID 2520233-Hydroxy-2-methylbenzoic AcidYield 56.3%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 962WaterSolvent

Conditions

Temperature
0 °C

Procedure

A solution of 3-benzyloxy-2-methylbenzoic acid (50 g, 0.21 mol) and sodium hydroxide (9 g, 0.225 mol) in 700 g of water and 2 g of 5% Pd/C catalyst (50% water-moist) are added to a 21 steel autoclave with an aerating stirrer. 10 bar of hydrogen are injected at a temperature of 50° C. and a stirring speed of 800 rpm. Consumed hydrogen is replaced by repeated injection. After 20 min, the absorption of hydrogen falls off. The catalyst is filtered off at room temperature by means of a pressure filter. 760.7 g of a crude solution are obtained, from which 7.7 g of toluene are separated off in a separating funnel. A total of 22.2 g of hydrochloric acid (37% strength) are added to the crude solution, then the solution is cooled to 0° C. The precipitated solid is filtered off with suction and washed twice with 50 g of water. After drying, 18.0 g of 3-hydroxy-2-methylbenzoic acid having a melting point of 147° C. are obtained. After concentration of the mother liquor, a further 9.6 g of substance can be obtained, such that the total yield is 27.6 g or 88.1% of theory.

Workup

  1. customare injected at a temperature of 50° C.
  2. customthe absorption of hydrogen
  3. filtrationThe catalyst is filtered off at room temperature by means of a pressure
  4. filtrationfilter
  5. custom760.7 g of a crude solution are obtained, from which 7.7 g of toluene
  6. customare separated off in a separating funnel
  7. additionA total of 22.2 g of hydrochloric acid (37% strength) are added to the crude solution
  8. filtrationThe precipitated solid is filtered off with suction
  9. washwashed twice with 50 g of water
  10. customAfter drying

Sources & evidence

ORD record
ord-53318ae9f0134428894db6a7d4cd4f2e
Source dataset
uspto-grants-1999_06
Patent number
US05910605

Reaction notes

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