反应详情

47.6 g of trityl chloride were added in small portions over 30 minutes to a mixture (cooled at -30° C.) of 32.2 g of the anti isomer of ethyl 2-(2-amino-4-thiazolyl)-2-hydroxyiminoacetate of Step A of Example 1, 90 ml of dry dimethylformamide and 24 ml of triethylamine and the mixture was left to spontaneous heating for 2 1/2 hours. Then, 150 ml of 2N hydrochloric acid and 600 ml of water were added thereto and the mixture was stirred for 15 minutes, then vacuum filtered. The recovered precipitate was empasted 3 times with ether and was then taken up in a mixture of methanol, water and triethylamine. The mixture was stirred and the vacuum filtered. The recovered product was rinsed with aqueous methanol and dried to obtain 60.2 g of the anti isomer of ethyl 2-(2-tritylamino-4-thiazolyl)-2-hydroxyiminoaetate. 3.4 g of the said product were recrystallized from a methylene chloride-methanol mixture to obtain 3 g of pure product melting at 260° C.

1. waitthe mixture was left
2. temperatureto spontaneous heating for 2 1/2 hours
3. filtrationvacuum filtered
4. additionwas then taken up in a mixture of methanol, water and triethylamine
5. stirringThe mixture was stirred
6. filtrationthe vacuum filtered
7. washThe recovered product was rinsed with aqueous methanol
8. customdried
9. customto obtain 60.2 g of the anti isomer of ethyl 2-(2-tritylamino-4-thiazolyl)-2-hydroxyiminoaetate
10. custom3.4 g of the said product were recrystallized from a methylene chloride-methanol mixture