反应详情

To a mixture of 2-(2-tert-pentyloxycarbonylamino-1,3-thiazol-4-yl)glyoxylic acid, which can be represented as 2-(2-tert-pentyloxycarbonylimino-2,3-dihydro-1,3-thiazol-4-yl)glyoxylic acid, (1.7 g.), sodium bicarbonate (0.5 g.), ethanol (10 ml.) and water (10 ml.) was added sodium borohydride (0.23 g.) under stirring and ice-cooling, and then the mixture was stirred for 1 hour at the same temperature. After the reaction, the reaction mixture was concentrated slightly. To the remaining reaction mixture were added 1 N sodium hydroxide aqueous solution (6 ml.) and diethyl ether (20 ml.), and then the aqueous layer was separated. To the aqueous layer was added ethyl acetate, and the mixture was adjusted to pH 1 to 2 with 10% hydrochloric acid and then the ethyl acetate layer was separated therefrom. The ethyl acetate layer was washed with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate and then treated with activated charcoal. The solvent was distilled off from the ethyl acetate layer to give brown powder of 2-hydroxy-2-(2-tert-pentyloxycarbonylamino-1,3-thiazol-4-yl)acetic acid, which can be represented as 2-hydroxy-2-(2-tert-pentyloxycarbonylimino-2,3-dihydro-1,3-thiazol-4-yl)acetic acid, (1.5 g.).

1. temperatureice-cooling
2. stirringthe mixture was stirred for 1 hour at the same temperature
3. customAfter the reaction
4. concentrationthe reaction mixture was concentrated slightly
5. customTo the remaining reaction mixture
6. customthe aqueous layer was separated
7. additionTo the aqueous layer was added ethyl acetate
8. customthe ethyl acetate layer was separated
9. washThe ethyl acetate layer was washed with a saturated aqueous solution of sodium chloride
10. dry with materialdried over magnesium sulfate
11. additiontreated with activated charcoal
12. distillationThe solvent was distilled off from the ethyl acetate layer