PROCESS FOR THE PREPARATION OF CEPHEM DERIVATIVES

摘要

The cephem derv. of formula (I) is prepd. by reacting triphenyl phosphine (Ph3P) and hexachloro ethane (C2Cl6) or carbon tetrachloride with the organic acid of formula (III) in the presence of org. solvent to prepare acyloxo phosphonium chloride cpd. of formula (IV); silyl-reacting 7-amino cephalosephoran acid (7-ACA) or its deriv. of formula (V) with an silylating agent opt. the base; then acylating the obtd. silyl prod. with the obtd. cpd. (IV) at -5--40 deg.C for 1-3 hrs.. In the formulas, R2 is H, acetoxy methyl, (1-methyl-1H-tetrazole-5-yl) thiomethyl or (2,5-dihydro-2-methyl-6-hydroxy-5-oxo-as-triazine-3-yl) thioethyl; R1 is H or metal salt. Pref, the org. solvent is dichloro methane, acetonitrile, or tetrahydrofuran; the silylating agent is dichlorodimethyl silane, chlorotrimethyl silane, hexadimethyl silazane, or N,O-bis-trimethy-silylacetate amide; the base triethyl amine, pyridine, or N,N-dimethyl aniline.