Ethylene Glycol → Syringic Acid

Participants

Reaction Steps

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.

Provenance & Evidence