- Preparation method of cefteram pivoxil
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The invention relates to a preparation method of cefteram pivoxil. The preparation method comprises following steps: taking 7-ACA and 5-methyltetrazole as starting raw materials, carrying out reactions in the presence of H2SO4 to generate 7-MTCA, protecting the amino groups of aminothiazol acetate, reacting aminothiazol acetate with 7-MTCA under the catalytic effect of AlMe3 to generate an intermediate (I); carrying out esterification reactions between the intermediate (I) and iodomethyl pivalate under the action of a phase transfer catalyst and an acid adsorbent, and removing the amino protection to obtain the target product (cefteram pivoxil). The reaction conditions are mild, the product purity and yield are high, and the technology is stable, is easy for amplification, and is suitablefor industrial production.
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- NOVEL INTERMEDIATES FOR SYNTHESIS OF CEPHALOSPORINS AND PROCESS FOR PREPARATION OF SUCH INTERMEDIATES
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A novel 4-halo-2-oxyimino-3-oxo butyric acid-N, N-dimethyl formiminium chloride chlorosulfate of formula (I) useful in the preparation of cephalosporin antibiotics, wherein X is chlorine or bromine; R is hydrogen, C1-4 alkyl group, an easily removable hydroxyl protective group, -CH2COOR5, or -C(CH3)2COOR5, wherein R5 is hydrogen or an easily hydrolysable ester group. The compound of formula (I) is prepared by reacting 4-halo-2-oxyimino-3-oxobutyric acid of formula (IV1), wherein X, R and R5 are as defined above, with N, N-dimethylformiminium chloride chlorosulphate of formula (VII), in an organic solvent at a temperature ranging from -30 °C to -15 °C. The cephalosporins that may be prepared from the intermediate include cefdinir, cefditoren pivoxil, cefepime, cefetamet pivoxil, cefixime, cefmenoxime, cefodizime, cefoselis, cefotaxime, cefpirome, cefpodoxime proxetil, cefquinome, ceftazidime, cefteram pivoxil, ceftiofur, ceftizoxime, ceftriaxone and cefuzonam.
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