Water → Salicylic Acid

HRID 1637149Notes

Reaction equation

HRID 1637149 reaction equation
[C:1]([O:10]C)(=[O:9])[C:2]1[C:3](=[CH:5][CH:6]=[CH:7][CH:8]=1)[OH:4].ClCC1C=CC(CCl)=CC=1.[OH-].[Na+].O>C1(C)C=CC=CC=1>[C:1]([OH:10])(=[O:9])[C:2]1[C:3](=[CH:5][CH:6]=[CH:7][CH:8]=1)[OH:4]

Participants

6

Reactant 4

HCID 962WaterHCID 4133Methyl Salicylate2×HCID 12171alpha,alpha'-Dichloro-p-xyleneHCID 14798Sodium Hydroxide

Product 1

HCID 338Salicylic Acid

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Conditions

Temperature
105 °C

Procedure

In a reactor equipped with a thermometer and a stirrer, 913 parts of methyl salicylate were charged, followed by heating to 100-110° C. At the same temperature, 525 parts of α,α'-dichloro-p-xylene were charged in portions over 5 hours. The resulting mixture was subjected to aging at 150° C. for 2 hours. The pressure of the reactor was reduced to 10 mmHg by a pump and unreacted methyl salicylate was separated for reuse at 150-180° C. After allowed to cool down to 100° C., 350 ml of toluene were added to the residue, whereby a toluene solution of a salicylic acid ester resin was obtained. In a reactor equipped with a thermometer and a stirrer, 160 parts of caustic soda and 907 parts of water were charged, followed by the dropwise addition of the above-obtained toluene solution at 85-90° C. over 4 hours. The temperature was raised to 100° C. so that the toluene was distilled off. After removal of insoluble matter, the residue was neutralized with 2,250 parts of an 8% aqueous solution of hydrochloric acid. The solid so precipitated was collected by filtration, washed with water and dried, whereby a salicylic acid resin was obtained in a yield of 705 parts. In a reactor equipped with a thermometer and a stirrer, 100 parts of the salicylic acid resin obtained above [composition (area %) according to a GPC analysis: 51.1% l=0, 22.3% l=1, 20.3% l=2, 4.3% l≥3, 1.0% others; number-average molecular weight: 543], 33.5 parts of benzyl chloride, 400 parts of 1,1,2-trichloroethane and 0.4 part of zinc chloride were charged, followed by reaction at 110° C. for 3 hours. After completion of the reaction, 1,000 parts of water were added and the 1,1,2-trichloroethane was azeotropically distilled off. The solid so precipitated was collected by filtration and dried, whereby 121 parts of an aralkylated salicylic acid resin were obtained. The resin was found to have a number-average molecular weight of 641 and a carboxylic acid equivalent of 251 g/eq.

Workup

  1. additionwere charged
  2. customwas separated for reuse at 150-180° C
  3. temperatureto cool down to 100° C.
  4. addition350 ml of toluene were added to the residue, whereby a toluene solution of a salicylic acid ester resin
  5. customwas obtained
  6. additionwere charged
  7. distillationwas distilled off
  8. customAfter removal of insoluble matter
  9. customThe solid so precipitated
  10. filtrationwas collected by filtration
  11. washwashed with water
  12. customdried

Sources & evidence

ORD record
ord-99989000edc94a6ca19a63d2f03729e7
Source dataset
uspto-grants-2000_03
Patent number
US06040111

Reaction notes

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