反应详情

温度

20 °C

A mixture of 4.94 g of the syn isomer of ethyl 2-hydroxyimino-2-(2-tritylamino-4-thiazolyl)-acetate hydrochloride in 10 ml of dimethylformamide was admixed under an inert atmosphere at room temperature over 3 minutes with 4.14 g of potassium carbonate and the mixture was stirred at 20° C. for 20 minutes. 8.65 ml of 1,2-dibromoethane were added thereto and the mixture was stirred for 30 hours and was then poured into a mixture of 100 ml of distilled water and 20 ml of methylene chloride. The decanted aqueous phase was extracted with methylene chloride and the combined organic phases were rinsed with distilled water. The wash water was reextracted with methylene chloride and the combined organic solution were dried and vacuum filtered. The filter was rinsed with methylene chloride and the filtrate was evaporated to dryness. The residue was chromatographed over silica gel and was eluted with benzene containing 5% ether. The first fraction was crystallized from methanol after dissolution at 50°-60° C. and was vacuum filtered at 0° to 5° C. to obtain 1.16 g of of the syn isomer of ethyl 2-(bromoethoxyimino)-2-(2-tritylamino-4-thiazolyl)-acetate in the form of a white cream product melting at 117° C. and a second homogeneous fraction of 1.258 of product was also obtained.

1. stirringthe mixture was stirred for 30 hours
2. extractionThe decanted aqueous phase was extracted with methylene chloride
3. washthe combined organic phases were rinsed with distilled water
4. customthe combined organic solution were dried
5. filtrationvacuum filtered
6. washThe filter was rinsed with methylene chloride
7. customthe filtrate was evaporated to dryness
8. customThe residue was chromatographed over silica gel
9. washwas eluted with benzene containing 5% ether
10. customThe first fraction was crystallized from methanol
11. dissolutionafter dissolution at 50°-60° C.
12. filtrationfiltered at 0° to 5° C.