Trihexylamine → L-Ascorbic Acid

Temperatur

78 °C

26.8 g (128.7 mmol) of ketogulonic acid methyl ester and 125 ml of acetonitrile were added under argon to a 500 ml sulphonation flask provided with a stirrer, thermometer, reflux condenser and 50 ml dropping funnel. Thereupon, the mixture was heated to 78° C. (reflux) while stirring. 34.7 g (100 mol %) of trihexylamine (99.4%) were then added dropwise within 15 minutes from the dropping funnel. The ester passed into solution completely after a reaction period of about 1 hour. After stirring for a total of 21/2 hours at reflux temperature, the orange-brown mixture was added to a rotary perforator gassed with nitrogen. Thereupon, the mixture was extracted continuously with about 500 ml of n-hexane for 20 hours. 1 hour after the beginning of the extraction, ascorbic acid crystallizes out slowly from the acetonitrile phase. After completion of the extraction, the content of the extractor was suction filtered. The yellowish crystals were washed with hexane and acetonitrile and dried overnight in a desiccator. There were obtained 20.6 g of ascorbic acid with a content of 99.5%, corresponding to a yield of 90.4%.

1. customprovided with a stirrer
2. temperaturethermometer, reflux condenser
3. temperature(reflux)
4. customcompletely after a reaction period of about 1 hour
5. temperatureat reflux temperature
6. additionthe orange-brown mixture was added to a rotary perforator
7. extractionThereupon, the mixture was extracted continuously with about 500 ml of n-hexane for 20 hours
8. extraction1 hour after the beginning of the extraction, ascorbic acid
9. customcrystallizes out slowly from the acetonitrile phase
10. extractionAfter completion of the extraction
11. filtrationfiltered
12. washThe yellowish crystals were washed with hexane and acetonitrile
13. customdried overnight in a desiccator

ORD-Eintrag

ord-55ef459ff07045299ead303ba57cfa65

Quelldatensatz

uspto-grants-1991_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05041563