| 摘要 |
<p>Prepn. of stable, crystalline cephalosporin cpds. of formula (I), free of the delta 2 isomer, comprises treating a cpd. of formula (II) where X = HCl or HI; Z = COOH and Q = Nu; or Z = COO(-) and Q = Nu(+); Q' = Nu or Nu(+)I(-); n = 0 or 1; Nu = N-heterocycle linked via S, of formula (a), (b), (c), (d) or (e); Nu(+) = N-contg. heterocycle linked through quat. N ring atom of formula (f), (g), (h) or (i); in CH2Cl2 when n = 1, or in CH2Cl2, 1,1,2-trichlorotrifluoroethane (freon TF) or 1,1,1-trichlorotrifluoroethane when n = 0, with lower alkanol (MeOH) to remove silyl gps., followed by acidification with HCl or HI, provided that when Nu(+) = 1-methyl-1-pyrrolidinio (h) and n = 0, the reaction is in Freon TF or 1,1,1-trichlorotrifluoroethane. Processes for (I) are also claimed: (i) including prepn. of the starting materials (II); and (ii) for prepn. of (I; Q = (h)) in an alternative embodiment.</p> |
