Dimethyl cyclohex-2-ene-1,4-dicarboxylate → Dimethyl terephthalate

HRID 385197Notes

Reaction equation

HRID 385197 reaction equation
[CH:1]1([C:11]([O:13][CH3:14])=[O:12])[CH2:6][CH2:5][CH:4]([C:7]([O:9][CH3:10])=[O:8])[CH:3]=[CH:2]1>C1CCCCC1.[Pt]>[C:7]([O:9][CH3:10])(=[O:8])[C:4]1[CH:5]=[CH:6][C:1]([C:11]([O:13][CH3:14])=[O:12])=[CH:2][CH:3]=1

Participants

4

Conditions

Temperature
150 °C

Procedure

In a Parr pressure reactor, dimethyl cyclohex-2-ene-1,4-dicarboxylate (2.42 g, 12.2 mmol) is dissolved in cyclohexane (120 ml, 0.10 M) and a catalytic amount of platinum on carbon (476 mg, 5 percent Pt/C, 1 mole percent platinum) powder is added. The reactor is pressurized with air (240 psi (1.65 MPa) at 23° C. after saturation of the solution) and its contents are heated at a 150° C. set-point temperature for 3 days under rapid stirring (160 rpm). After opening the cooled Parr reactor, a suspension of black platinum on carbon (Pt/C) in a near colorless solution is present. All solvent is removed from a sample of the suspension, and the entire residue is dissolved in CDCl3 for 1H NMR analysis. Integration of the respective resonances shows the presence of about 23 percent unreacted dimethyl cyclohex-2-ene-1,4-dicarboxylate starting material, of about 59 percent dimethyl terephthalate oxidation product, and of about 18 percent dimethyl cyclohexane-1,4-dicarboxylate disproportionation by-product. Column chromatography (Si35, SF40-150g, AnaLogix column with 10 percent ethyl acetate/hexane isocratic eluent) provides pure dimethyl terephthalate.

Workup

  1. customat 23° C.
  2. customAll solvent is removed from a sample of the suspension
  3. dissolutionthe entire residue is dissolved in CDCl3 for 1H NMR analysis

Sources & evidence

ORD record
ord-ed5a41b72e1e43358b9ab32df8e72705
Source dataset
uspto-grants-2013_02
Patent number
US08367858B2

Reaction notes

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