Ethylene Glycol → Syringic Acid
Reaction equation
[CH3:1][O:2][C:3]1[C:8]([O:9]C)=[C:7]([O:11][CH3:12])[CH:6]=[C:5]([CH:13]=[O:14])[CH:4]=1.C(O)C[OH:17]>>[C:13]([OH:14])(=[O:17])[C:5]1[CH:6]=[C:7]([O:11][CH3:12])[C:8]([OH:9])=[C:3]([O:2][CH3:1])[CH:4]=1Participants
Procedure
106 g (0.5 mole) of TMBA, 66 g (1.6 mole) of soda in pellets in 200 g of ethylene glycol, are heated under nitrogen. Solution is complete towards 160° C. Distillation commences and stops at the end of 30 minutes, at around 195° C. This temperature is held for 30 minutes. After cooling under nitrogen, it is diluted with 1 l of water and acidified to pH 3 with 170 ml of 10 N sulphuric acid, with heating to bring it to reflux. It is then cooled and left to crystallize for 1 hour. By filtration, 163.3 g of moist, crude product are isolated and this recrystallized in 900 ml of water. After washing and drying, 76.4 g of recrystallized syringic acid are obtained, namely a yield of 77.2% with respect to the TMBA. The acid obtained has a melting point of 210° C. Analysis by liquid-liquid chromatography indicates that it contains less than 1% of residual TMBA and that it is free of 3-hydroxy 4,5-dimethoxybenzoic acid and of dihydroxymonomethoxybenzoic acid.
Workup
- customis complete towards 160° C
- distillationDistillation commences and stops at the end of 30 minutes
- customat around 195° C
- temperatureAfter cooling under nitrogen
- additionit is diluted with 1 l of water
- temperaturewith heating
- temperatureto reflux
- temperatureIt is then cooled
- waitleft
- customto crystallize for 1 hour
- filtrationBy filtration, 163.3 g of moist, crude product
- customare isolated
- customthis recrystallized in 900 ml of water
- washAfter washing
- customdrying
Sources & evidence
- ORD record
- ord-2acd145c5ef049408ca2c91f8d4fd8a1
- Source dataset
- uspto-grants-1980_03
- Patent number
- US04191841
Reaction notes
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