- 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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- Method for producing cephalosporins
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A method for producing cephalosporins 7-substituted with an amino-thiazolylacetic group by reacting 7-ACA or its derivatives having the amino group and the carboxyl protected with reactive derivatives of amino-thiazolylacetic acid.
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- 2-chloro-4,6-dimethoxy-1,3,5-triazine: A new effective and convenient coupling reagent for cephalosporin derivatives
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Chloro-4,6-dimethoxy-1,3,5-triazine(CDMT) 2 was reacted with 2-(2- amino-4-thiazolyl)-2-syn-alkoxyiminoacetic acid 1 to give an active ester intermediate 3.
- Lee, Hong-Woo,Kang, Tae Won,Cha, Kyung Hoi,Kim, Eung-Nam,Choi, Nam-Hee,Kim, Jung-Woo,Hong, Chung Il
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p. 1339 - 1349
(2007/10/03)
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- Diethyl chlorophosphate: An effective and convenient coupling reagent of cephalosporin derivatives
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A coupling reagent, diethyl chlorophosphate (DECP) 2, was reacted with 2-(2-amino-4-thiazolyl)-2-syn-alkoxyiminoacetic acid 1 to give an active ester intermediate 3.
- Lee, Hong-Woo,Kang, Tae Won,Cha, Kyung Hoi,Kim, Eung-Nam,Choi, Nam-Hee,Kim, Jung-Woo,Hong, Chung Il
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- Alkyloximes of 7-amino-thiazolyl-acetamido-cephalosporanic acids
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Novel alkyloximes of 7-amino-thiazolyl-acetamidocephalosporanic acids of the formula STR1 wherein R is selected from the group consisting of alkyl of 1 to 5 carbon atoms, cycloalkyl of 3 to 5 carbon atoms and --CH2 --SR', R' is selected from the group consisting of acyl of an alkanoic acid of 2 to 4 carbon atoms, 1-methyl-tetrazolyl and 2-methyl-1,3,4-thiadiazolyl, R1 is selected from the group consisting of hydrogen and a group easily removeable by acid hydrolysis or hydrogenolysis, R2 is selected from the group consisting of alkyl of 1 to 4 carbon atoms and alkenyl and alkynyl of 2 to 4 carbon atoms, A is selected from the group consisting of hydrogen, an alkali metal cation, an equivalent of an alkaline earth metal or magnesium, an organic amine base cation and an ester group easily removeable by acid hydrolysis or hydrogenolysis with the proviso that when R1 is hydrogen, A is not an ester group easily removeable by hydrogenolysis or acid hydrolysis and the wavy line means that OR2 is in one or the other of the two possible syn or anti isomeric positions having a very good antibiotic activity and novel processes and intermediates for their preparation.
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