反应详情

温度

60 °C

To a mixture solvent of toluene (570 ml) and acetone solution containing 23.5 weight % of hydrogen chloride (65 ml as acetone) was added 2-keto-L-gulonic acid (content 91.2%, water content 8.4%)(100 g). To this solution were further added water (7.7 ml) and trimethylcetylammonium chloride (110 mg)(water content was 1.90 times as much in molar ratio relative to 2-keto-L-gulonic acid). The reaction mixture was stirred for six hours while heating at 60° C., which was then cooled to 20° C. The resultant was poured into water (1 l), and the mixture was stirred, which was then left standing, followed by separating the aqueous layer. To the organic layer was added water (400 ml) for re-extraction. The aqueous layers were combined and subjected to quantitative determination by means of a high performance liquid chromatography to reveal the existence of L-ascorbic acid[78.2 g (yield 94.5%)], while unreacted 2-keto-L-gulonic acid remaining in an amount of 2.7%. The absorbance (E430nm1%) of this aqueous layer was 0.160.

1. temperaturewhich was then cooled to 20° C
2. stirringthe mixture was stirred
3. waitwhich was then left standing
4. customby separating the aqueous layer
5. additionTo the organic layer was added water (400 ml)
6. extractionfor re-extraction