反应详情

To a solution of ethyl 2-[2-(N-methyl-N-tert-pentyloxycarbonylamino)-1,3-thiazol-4-yl]glyoxylate (3.1 g.) in ethanol (40 ml.) was added 1 N sodium hydroxide aqueous solution (14.2 ml.) under ice-cooling and stirring, and the mixture was further stirred for 30 minutes at the same temperature. After the reaction, ethanol was distilled off from the reaction mixture below 20° C. under reduced pressure. To the residue was added water (50 ml.), and after layering with ethyl acetate, the mixture was adjusted to pH 3 with 2 N hydrochloric acid. The ethyl acetate layer was separated from the mixture, washed with water, dried over magnesium sulfate and then treated with an activated charcoal. The solvent is distilled off from the resulting ethyl acetate layer to give solid of 2-[2-(N-methyl-N-tert-pentyloxycarbonylamino)-1,3-thiazol-4-yl]glyoxylic acid (2.4 g.).

1. temperaturecooling
2. stirringthe mixture was further stirred for 30 minutes at the same temperature
3. distillationwas distilled off from the reaction mixture below 20° C. under reduced pressure
4. additionTo the residue was added water (50 ml.)
5. customThe ethyl acetate layer was separated from the mixture
6. washwashed with water
7. dry with materialdried over magnesium sulfate
8. additiontreated with an activated charcoal
9. distillationThe solvent is distilled off from the resulting ethyl acetate layer