反应详情

A mixture of 2-(2-formamidothiazol-4-yl)-2-(2-aminoethoxyimino)acetic acid (syn isomer, 0.80 g.) and triethylamine (0.45 g.), in a solution of a saturated aqueous solution of sodium bicarbonate (4 ml.), tetrahydrofuran (35 ml.) and water (25 ml.) was adjusted to pH 8.5 with hydrochloric acid. 2-Phenyl-2-(tert-butoxycarbonyloxyimino)acetonitrile (0.77 g.) was added to the stirred solution and stirred at room temperature for 3 hours. After distilling off tetrahydrofuran from the resultant solution, the aqueous solution was washed with diethyl ether, and adjusted to pH 1.5 with 85% phosphoric acid. The solution was extracted with ethyl acetate (50 ml.), and the extract was washed with a saturated aqueous solution of sodium chloride (10 ml.), dried over magnesium sulfate and concentrated under reduced pressure to give 2-(2-formamidothiazol-4-yl)-2-(2-tert-butoxycarbonylaminoethoxyimino)acetic acid (syn isomer, 0.40 g.).

1. distillationAfter distilling off tetrahydrofuran from the resultant solution
2. washthe aqueous solution was washed with diethyl ether
3. extractionThe solution was extracted with ethyl acetate (50 ml.)
4. washthe extract was washed with a saturated aqueous solution of sodium chloride (10 ml.)
5. dry with materialdried over magnesium sulfate
6. concentrationconcentrated under reduced pressure