- Cefetamet pivoxil hydrochloride preparation method
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The invention relates to a cefetamet pivoxil hydrochloride preparation method, which comprises: generating an intermediate I by using 7-ADCA and ethyl methylaminothiazolyloximate as starting raw materials under the catalysis of AlMe3; and carrying out an esterification reaction on the intermediate I and iodomethyl pivalate under the actions of a phase transfer catalyst and an acid adsorbent, carrying out salt formation on the esterified product, and crystallizing to obtain the target product cefetamet pivoxil hydrochloride. According to the present invention, the method has characteristics ofmild reaction conditions, high product purity, high yield and stable process, and is suitable for industrial production.
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Page/Page column 6-9
(2018/10/19)
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- A process for the preparation of cephalosporin he beautiful acid
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The invention relates to a method for preparing cefetamet acid. The method comprises the procedures of synthesis, decoloring, adsorption and crystallization. Due to improvement of the procedures of synthesis, decoloring and adsorption, impurities are reduced, the yield of cefetamet acid is increased, and the purity is improved. The method for preparing cefetamet acid, which is provided by the invention, is mild in reaction conditions, stable in process and applicable to industrial large-scale production.
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Paragraph 0007;0037; 0038
(2017/02/23)
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- IMPROVED PROCESS FOR THE PREPARATION OF CEPHALOSPORIN ANTIBIOTICS
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Abstract The present invention more particularly relates to a process for the preparation of cephalosporin antibiotics of the Formula (I) wherein R1 represents hydrogen, trityl, alkyl like CH3, CRaRbCOORc where Ra and Rb independently represent hydrogen or methyl and Rc represents hydrogen or (C1-C6) alkyl; R2 is carboxylate ion or COORd, where Rd represents hydrogen, ester or a counter ion which forms a salt; R3 represents hydrogen, CH3, CH2OCH3, CH2OCOCH3, CH=CH2, Formula (II).
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Page/Page column 10-11
(2008/06/13)
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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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- Preparation of new intermediates and their use in manufacturing of cephalosporin compounds
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The present invention provides new thioester derivatives of 4-halogeno-2-methoxyimino-3-oxo-butyric acid of the general formula (I), also, the invention provides a method by which the said thioester derivatives can be prepared by reacting 4-halogeno-2-methoxyimino-3-oxo-butyric acid of the general formula (II) with 2-mercapto-5-substituted-1,3,4-oxadiazoles of the general formula (III) in a solvent, in the presence of DMF/POCl3and in presence of an organic base and if desired the so obtained thioester derivatives so obtained are reacted with 7-amino-cephem carboxylic acids of the general formula (V) to produce condensed products which are insitu reacted with thiourea to get cephalosporin antibiotic compounds having the general formula (VI).
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- Thioester derivatives of thiazolyl acetic acid and their use in the preparation of cephalosporin compounds
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The present invention provides novel thioester derivatives of thiazolyl acetic acid of the general formula (I), wherein, R1represents H, trityl, CH3, or CRaRbCOOR3, in which Raand Rb, independently of one another, represents hydrogen or methyl and R3represents H or C1-C7alkyl; and R2represents C1-C4alkyl or phenyl. The invention also provides a method for preparation of the thioester derivatives and reaction of the thioester derivatives with cephem carboxylic acids to produce cephalosporin antibiotic compounds having general formula (II), wherein, R1represents H, trityl, CH3, or CRaRbCOOR3, in which Raand Rb, independently of one another, represents hydrogen or methyl and R3represents H or C1-C7alkyl; R4is CH3, —CH═CH2, CH2OCH3, CH2OCOCH3, and R5is H or a salt or a carboxylic protecting group, comprising, acylating a compound of formula (III), wherein, R4and R5are defined as above, and R6is H or trimethylsilyl; with a compound of formula (I).
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- Process for producing cephalosporin antibiotics
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A process for preparing certain cephalosporin antibiotics, namely, cefotaxime, cefetemet, and ceftriaxone sodium comprising acylation of 7-amino-3-cephem-4-carboxylic acid derivatives with 2-mercapto-5-methyl-1,3,4-thiadiazolyl-(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetate having the formula: STR1
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- Process for the preparation of derivative of 7-[(2-hydroxyimino)-acetamido]-cephalosporanic acid
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A novel process for the preparation of syn isomers of cephalosporanic acid derivatives of the formula STR1 comprising reacting first in a solvent and optionally in the presence of a base, a compound of the formula STR2 with a compound of the formula wherein R4 is selected from the group consisting of optionally substituted alkyl, aryl and aralkyl and Hal is a halogen and reacting the resulting product in a solvent and optionally in the presence of a base with a compound of the formula STR3 to obtain the compound of formula I' which are known to possess good antibiotic properties.
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- NEW SYNTHESIS OF OXIME-TYPE BETA-LACTAM ANTIBIOTICS
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Reacton of anhydrous acids II with phosphorus pentachloride afforded hydrochlorides of chlorides III which were used in acylations of N,O-bis(trimethylsilyl) derivatives of 6-aminopenicillanic acid and 7-aminodeacetoxycephalosporanic acid.Change of the (Z)-configuration of the alkoxyimino group during the synthesis was observed only in the methoxyimino series.The prepared penicillins IV are effective against gram-positive as well as gram-negative bacteria.
- Mandel, Martin,Novak, Ludvik,Rajsner, Miroslav,Holubek, Jiri,Hola, Vladislava
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p. 1734 - 1745
(2007/10/02)
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- Determination of cephalosporins and decomposition products by liquid chromatography with indirect electrochemical detection
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Indirect electrochemical detection, using in-line electrochemically generated bromine as oxidizing agent, has been used for the determination of cephalosporins with liquid chromatography. The method presents a general detection principle for cephalosporins since it is related to their basic structure. The detection limits obtained, which were between 0. 4 and 3 ng, and the repeatability with a relative standard deviation below 1. 5% comply with the requirements for drug stability studies in vitro.
- Fabre,Kok
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p. 136 - 141
(2007/10/02)
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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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