• YAKHAK HOEJI
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• v.50 no.6
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• pp.393-397
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• 2006

The synthesis of new 3-substituted 7-halocephalosporanates was described. 7-ACA was reacted with thiols at pH 6.5${\sim}$6.8 to afford the 3-substituted 7-ACA (1), which was treated with diphenyldiazomethane to give diphenylmethyl 7-aminocephalosporanate (2). The Halogenation of 7-aminocephalosporanate (2) with NaNO$_2$, KBr and H$_2$SO$_4$ gave 7-bro-mocephalosporanate (3) and with NaNO$_2$, HCI gave 7-chlorocephalosporanate (4). Diphenylmethyl cephalosporanate (2${\sim}$4) were deprotected by AIC1$_3$ in anisole and neutralized to give the sodium cephalosporanate (5${\sim}$7).