反应详情

0.23 of dicyclohexylcarbodiimide were added under argon at 20° C. to a mixture of 1.002 g of the syn isomer of 2-(2-tritylamino-4-thiazolyl)-2-(1-methyl-1-methoxy-ethoxyimino)-acetic acid and 3 ml of methylene chloride and the mixture was stirred at 20°-25° C. for one hour to obtain a suspension of dicyclohexylurea. In a second flask, 0.28 ml of triethylamine were added at 20° to 25° C. to a suspension of 0.344 g of 3-[(5-methyl-1,3,4-thiadiazol-2-yl)-thiomethyl]-7-amino-ceph-3-eme-4-carboxylic acid in 2 ml of nitromethane to form a brown solution which was added over 5 minutes with stirring at 20°-25° C. to the first suspension. The mixture was rinsed with methylene chloride and was then stirred for 2 hours and was vacuum filtered to remove dicyclohexylurea (0.2 g). The filter was rinsed with methylene chloride and the filtrate and 8 ml of N hydrochloric acid were stirred. The mixture was vacuum filtered and the brown product was rinsed with water and methylene chloride to obtain 0.4 g of mainly the starting product. The filtrate was washed with distilled water until the wash water was neutral, dried and distilled to dryness under reduced pressure. The residue was added to 5 ml of ethyl acetate and the mixture was vacuum filtered at room temperature. The product was rinsed with ethyl acetate to obtain 0.32 g of the syn isomer of 2-(2-tritylamino-4-thiazolyl)-2-hydroxyimino-acetic acid.

1. customto obtain
2. customto form a brown solution which
3. additionwas added over 5 minutes
4. stirringwith stirring at 20°-25° C. to the first suspension
5. washThe mixture was rinsed with methylene chloride
6. stirringwas then stirred for 2 hours
7. filtrationfiltered
8. customto remove dicyclohexylurea (0.2 g)
9. washThe filter was rinsed with methylene chloride
10. stirringthe filtrate and 8 ml of N hydrochloric acid were stirred
11. filtrationfiltered
12. washthe brown product was rinsed with water and methylene chloride
13. customto obtain 0.4 g of mainly the starting product
14. washThe filtrate was washed with distilled water until the wash water
15. customdried
16. distillationdistilled to dryness under reduced pressure
17. additionThe residue was added to 5 ml of ethyl acetate
18. filtrationfiltered at room temperature
19. washThe product was rinsed with ethyl acetate