反应详情

To a solution of ethyl 2-(2-methylamino-1,3-thiazol-4-yl)acetate, which can be represented as ethyl 2-(2-methylimino-2,3-dihydro-1,3-thiazol-4-yl)acetate, (8 g.) in a mixture of pyridine (80 ml.) and methylene chloride (40 ml.) was dropwise added tert-pentyl chloroformate over 2 hours at -25° to -20° C. with stirring, and the mixture was stirred for 30 minutes at the same temperature. After the reaction, the reaction mixture was poured into water (200 ml.), the mixture was extracted with ethyl acetate (300 ml.), and then the organic layer was separated. The organic layer was washed with 2 N hydrochloric acid, water, 5% sodium bicarbonate aqueous solution and water in turn. The organic layer was dried over magnesium sulfate and then concentrated to give oil of ethyl 2-[2-(N-methyl-N-tert-pentyloxycarbonylamino)-1,3-thiazol-4-yl]acetate (14.5 g.).

1. customover 2 hours
2. customat -25° to -20° C.
3. stirringthe mixture was stirred for 30 minutes at the same temperature
4. customAfter the reaction
5. extractionthe mixture was extracted with ethyl acetate (300 ml.)
6. customthe organic layer was separated
7. washThe organic layer was washed with 2 N hydrochloric acid, water, 5% sodium bicarbonate aqueous solution and water in turn
8. dry with materialThe organic layer was dried over magnesium sulfate
9. concentrationconcentrated