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| | DEHYDROASCORBIC ACID Basic information |
| | DEHYDROASCORBIC ACID Chemical Properties |
| Melting point | 228 °C (dec.)(lit.) | | alpha | D20 +56° | | Boiling point | 389.3±38.0 °C(Predicted) | | density | 1.743±0.06 g/cm3(Predicted) | | storage temp. | -20°C | | solubility | DMSO (Slightly, Heated), Methanol (Slightly, Sonicated) | | form | Solid | | pka | 3.90(at 25℃) | | color | White to Dark Orange | | Merck | 13,2886 | | Stability: | Light Sensitive | | LogP | -1.702 (est) | | CAS DataBase Reference | 490-83-5(CAS DataBase Reference) |
| Hazard Codes | Xn | | Risk Statements | 22 | | WGK Germany | 3 | | F | 1-8-10 | | HS Code | 2936270000 |
| | DEHYDROASCORBIC ACID Usage And Synthesis |
| Chemical Properties | Orange Solid | | Uses | The reversibly oxidized form of ascorbic acid. | | Definition | ChEBI: Dehydroascorbic acid having the L-configuration. | | Purification Methods | Crystallise dehydro-L(+)-ascorbic acid from MeOH. The anhydrous acid is formed by heating it in a vacuum at 100o/1hour to give a crisp glassy product which when shaken with absolute EtOH and then kept at 0o for 2days gives microcrystals of the anhydrous acid. This is then washed with absolute EtOH and dried in a vacuum. It has m 225o(dec) and is stable in acidic solution but decomposes rapidly in alkaline solution. A 1% solution of the anhydrous acid when dissolved in phthalate/HCl buffer pH 3.5 at 60o and cooled to 20o has [] 20D +56o(0minutes), +53.5o(2hours), +19o(3days), -2o(5days) and -6o(6days); then it becomes orange in colour. A freshly prepared 1% solution in H2O has [] D +50o(0minutes), +44o(2hours), +16o(3days) and 0o(5days). [Herbert et al. J Chem Soc 1270 1933, Kenyon et al. J Chem Soc 158 1948, Beilstein 18/5 V 411.] |
| | DEHYDROASCORBIC ACID Preparation Products And Raw materials |
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