Methanol → Dimethyl 2,5-dimethylbenzene-1,4-dicarboxylate

HRID 906132Notes

Reaction equation

HRID 906132 reaction equation
[CH3:1][C:2]1[CH:10]=[C:9](C(O)=O)[C:8]([CH3:14])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[CH3:15][OH:16].[CH3:17][Si](C=[N+]=[N-])(C)C.C[CH2:25][O:26]CC>>[CH3:14][C:8]1[CH:7]=[C:3]([C:4]([O:6][CH3:17])=[O:5])[C:2]([CH3:1])=[CH:10][C:9]=1[C:15]([O:26][CH3:25])=[O:16]

Participants

5

Reactant 4

HCID 887MethanolHCID 3283Diethyl EtherHCID 167693TrimethylsilyldiazomethaneHCID 2999892,5-Dimethylterephthalic Acid

Product 1

HCID 289462Dimethyl 2,5-dimethylbenzene-1,4-dicarboxylateYield 93%

Procedure

2,5-Dimethylterephthalic acid (3 g, 15.5 mmol) was suspended in ether (30 mL) and methanol (10 mL) and was cooled in an ice bath. (Trimethylsilyl)diazomethane (2 M solution in hexanes; 16 mL) was added drop-wise. The mixture was stirred at ambient temperature for 0.5 h and then was quenched with acetic acid (2 mL) and was concentrated. The residue was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate. The organic portion was washed with brine, dried over sodium sulfate, then filtered and was concentrated to afford dimethyl 2,5-dimethylterephthalate (3.18 g, 14.3 mmol, 93% yield). 1H NMR (400 MHz, CDCl3): δ 7.76 (s, 2H), 3.91 (s, 6H), 2.57 (s, 6H); MS (EI) for C12H14O4: 223 (MH+).

Workup

  1. customwas quenched with acetic acid (2 mL)
  2. concentrationwas concentrated
  3. customThe residue was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate
  4. washThe organic portion was washed with brine
  5. dry with materialdried over sodium sulfate
  6. filtrationfiltered
  7. concentrationwas concentrated

Sources & evidence

ORD record
ord-a8399a0c791c41c987a3fc1f4ce2cf9a
Source dataset
uspto-grants-2011_09
Patent number
US08012956B2

Reaction notes

Loading…