| 摘要 |
<p>Cephalosporin analogs useful in the preparation of cephalosporin type antibiotics are disclosed, being compounds of the formula <IMAGE> where X is NH2, N3 or phthalylimino; R1 is H, Ha, OH or alkoxy, aryloxy, aralkyloxy, acyloxy, sulfonyloxy, alkylthio, arylthio, aralkylthio, alkylsulfinyl, arylsulfinyl, aralkylsulfinyl sulfonium, quaternary ammonium, alkylsulfonyl, arylsulfonyl, aralkylsulfonyl, arylselenyl or arylseleninyl; R2 is as defined for R2 plus alkyl, haloalkyl, N3 nitrile, amino or substituted amino; and R3 is H, or substituted or unsubstituted alkyl, aryl, aralkyl or silyl. Acid addition salts, where X is NH2 and acid salts, where R3 is H are also disclosed.</p> |
