Water → Monomethyl terephthalate

HRID 1762142Notes

Reaction equation

HRID 1762142 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 in 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, R3 =(CH3)2CCH2 (CH3)2, R3 =CH3) as pale yellow needles having a melting point of 161°-162 ° C. when crystallized from CH2Cl2 /hexane. (b)To a solution of 80 mg of the thus obtained rearranged product in 5 ml of acetic acid was added 0.2 ml of sulfuric acid and the mixture refluxed for 30 minutes, whereafter the reaction mixture was poured into water and extracted with ethyl acetate. The resulting organic layer was washed with water until the pH of the washing became 7 and dried over MgSO4. The distillation of the solvent and purification by chromatography through silica gel column gave 32 mg (yield: 41.8%) of the flavone carboxylic acid ester(III; R1, R2 =(CH3)2CCH2CH2C(CH3)2,R3 =CH3,R4 =H;No.4) as colorless flakes having a melting point of 175°-176° C. (recrystallized from methylenechloride/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-c2854a9e56e24b40a1172e394b4c6b04
Source dataset
uspto-grants-1989_05
Patent number
US04831052

Reaction notes

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