Ammonia → 7-Amino-3-methoxymethyl-3-cephem-4-carboxylic acid

Temperature

0 °C

4.1 ml of concentrated sulfuric acid was added to 80 me of sulfolane and the resulting mixture was cooled to about 0° C. 8.2 ml of trimethyl borate was added dropwise thereto and 10 g of 7-aminocephalosporanic acid was added thereto in small portions. 8.4 ml of antimony pentachloride was added dropwise thereto at about 0° C., stirred at 0 ° C. for additional 6 hours, and then, the resulting mixture was added to ice-water. The pH of the mixture was adjusted to 3.4 with aqueous ammonia. The ocherous solid formed was isolated by filtration and washed with water. The wet solid was dispersed in water and the pH of the resulting mixture was adjusted to 8 with aqueous ammonia to dissolve the solid in water, and then, the pH of the resulting mixture was adjusted to 3.5 with 3N hydrochloric acid. The resulting mixture was filtered to obtain crystals which were washed with water, and then, dried overnight in a vacuum to give 1.75 g of 7-amino-3-methoxymethyl-3-cephem-4-carboxylic acid as an ocherous solid (Yield: 20% and Purity: 94.3%). H-NMR data was equal to that of the compound prepared in Example 1.

1. customThe ocherous solid formed
2. customwas isolated by filtration
3. washwashed with water
4. additionThe wet solid was dispersed in water
5. dissolutionto dissolve the solid in water
6. filtrationThe resulting mixture was filtered
7. customto obtain crystals which
8. washwere washed with water
9. customdried overnight in a vacuum

ORD record

ord-a3ed0392ecdd4bcbb85e62f5670ce1a9

Source dataset

uspto-grants-2003_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06620930B1