Water → Monomethyl terephthalate

HRID 1650906Notes

Reaction equation

HRID 1650906 reaction equation
OC1C=CC=CC=1C(=O)C.[Cl-].[CH3:12][O:13][C:14](=[O:24])[C:15]1[CH:23]=[CH:22][C:18]([C:19]([OH:21])=[O:20])=[CH:17][CH:16]=1.O>N1C=CC=CC=1>[CH3:12][O:13][C:14](=[O:24])[C:15]1[CH:23]=[CH:22][C:18]([C:19]([OH:21])=[O:20])=[CH:17][CH:16]=1

Participants

5

Reactant 3

HCID 962WaterHCID 83752'-HydroxyacetophenoneHCID 53442854Terephthalic acid monomethylester chloride

Product 1

HCID 15513Monomethyl terephthalateYield 80%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

To a solution of 448 mg of the thus-obtained o-hydroxyacetophenone in 6 ml of pyridine was added 1.6 g of terephthalic acid monomethylester chloride and the mixture stirred at room temperature for one night. The reaction mixture was poured over water and extracted with ethyl acetate and washed with dilute hydrochloric acid, water, 1N hydrogencarbonate, water, saturated saline solution and dried over MgSO4. The distillation of the solvent and purification by chromatography through silica gel column gave 600 mg (yield: 80.0%) of the derivative of terephthalic acid methyl ester. To a solution of 210 ml of the thus-obtained methylester in 5 ml of pyridine was added 70 mg of caustic potash and the mixture stirred at room temperature for one night. The reaction mixture was poured over 30 ml of 20% acetic acid and then extracted with ethyl acetate. The organic layer was washed with water 2-3 times and dried over MgSO4. The distillation of the solvent and purification by chromatography through silica gel column gave 112 mg (yield: 53.3%) of the rearranged product (IV; R1, R2 =(CH3)2CCH2CH2C(CH3)2, R3 =CH3) as pale yellow needles having a melting point of 161°-162° C. when crystallized from CH2Cl2 /hexane.

Workup

  1. extractionextracted with ethyl acetate
  2. washwashed with dilute hydrochloric acid, water, 1N hydrogencarbonate, water, saturated saline solution
  3. dry with materialdried over MgSO4
  4. distillationThe distillation of the solvent and purification by chromatography through silica gel column

Sources & evidence

ORD record
ord-0fb4ffcf57134742821da68afaa3ec13
Source dataset
uspto-grants-1990_05
Patent number
US04925979

Reaction notes

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