| 摘要 |
<p>1491986 Cephalosporin derivatives SANGYOKAGAKU-KENKYUKYOKAI 14 July 1976 [17 July 1975] 30047/75 Heading C2C Novel compounds I (-COOR is free or esterified carboxyl; Z is O or S; R<SP>3</SP> and R<SP>4</SP> are H, or alkyl, or NR<SP>3</SP>R<SP>4</SP> is heterocyclyl with or without an O atom, which ring may be substituted by carbamoyl; and Y is H, azido, alkanoyloxy, alkoxy, carbamoyloxy, alkylthio or heterocyclylthio) and salts thereof are prepared by reaction of a compound II (-COOR<SP>1</SP> is esterified or protected carboxyl and -COOR<SP>2</SP> is free, esterified or protected carboxyl) with an appropriate carbamoylating or thiocarbamoylating agent, followed where necessary by removal of the protecting group. Pharmaceutical compositions comprise a compound I together with a suitable carrier and/or diluent.</p> |
