头孢唑肟钠有关物质的研究

摘要：目的 采用液相色谱法和液相色谱-质谱联用法对不同批次的头孢唑肟钠粉针中的杂质进行全面深入研究。方法 对头孢唑肟钠进行加速稳定性试验,采用液相色谱、液质联用仪检测头孢唑肟钠中的杂质类型,采用制备型液相色谱制备有关杂质,经波普分析确定各杂质的结构。结果 共检出12种杂质,其中2种为新检出的杂质,且在制剂中含量较高,本次报道的杂质为B (6R,7R)-7-((Z)-2-(2-氨基噻唑-4-基)-2-(甲氧基亚氨基)乙酰胺-8-氧代-5-噻-1-氮杂双环[4,2,0]辛-3-烯-2-羧酸,C 2-(R)-((Z)-2-(2-氨基噻唑-4-基)-2-(甲氧基亚氨基)乙酰胺(羧基)甲基)-3,6-二氢-2H-1,3-噻嗪-4-羧酸,D 2-((R)-(Z)-2-(2-氨基噻唑基) -2-(甲氧基亚氨基)乙酰胺(羧基)甲基)-3,6-二氢-2H-1,3-噻嗪-4-羧酸,F (Z)-2-((2-(2-氨基噻唑-4-基)-2-(甲氧基亚氨基)乙酰胺)甲基)-3,6-二氢-2H-1,3-噻嗪-4-羧酸,G 2-((R)-((E)-2-(2-氨基噻唑-4-基)-2-(甲氧基亚氨基)乙酰胺基(羧基)甲基)-3,6-二氢-2H-1,3-噻嗪-4-羧酸,H 2-((R)-(E)-2-(2-氨基噻唑-4-基)-2-(甲氧基亚氨基)乙酰胺基(羧基)甲基)-3,6-二氢-2H-1,3-噻嗪-4-羧酸,I (6R,7R)-7-((E)-2-(2-氨基噻唑-4-基)-2-(甲氧基亚氨基)乙酰胺基)-8-氧基-5-噻-1-氮杂双环[4,2,0]辛-3-烯-2-羧酸,J (6R)-7-((Z)-2-(2-氨基噻唑-4-基)-2-(甲氧基亚氨基)乙酰胺)-8-氧代-5-噻-1-氮杂双环[4,2,0]辛-2-烯-2-羧酸。结论 本文报道的分析方法能较好的检测分析头孢唑肟钠中的各种可能的常见杂质,本实验室开发的分离纯化方法能够分离得到纯度合乎结构确证要求的杂质,用NMR、HRMS、NOE和CD等分析方法能准确推测这些杂质的结构。     

Studies on beta-lactam antibiotics. I. Synthesis and in vitro anti-pseudomonal activity of 3-isothiazole-cephalosporin derivatives

The synthesis and in vitro activity of 7 beta-[(Z)-2-(2-amino-4-thiazolyl)-2-(2-carboxy-2- alkoxyimino)acetamido]cephalosporins with a (4-carboxy-3-hydroxy-5-isothiazolyl)thiomethyl group at the 3-position are described. These cephalosporins (9a approximately 9i) showed excellent activity against Gram-negative bacteria including beta-lactamase producing strains. The most interesting compound of the series was 7 beta-[(Z)-2-(2-amino-4-thiazolyl)-2- (2-carboxy-2-propoxyimino)acetamido]-3-cephem-4-carboxylic acid (9g, YM-13115) because of its outstanding inhibitory potency against Pseudomonas aeruginosa and highly prolonged plasma half-life in rats.     

Studies on beta-lactam antibiotics. IX. Synthesis and biological activity of a new orally active cephalosporin, cefixime (FK027)

The synthesis and some biological properties of 7 beta-[(Z)-2-(2-amino-4-thiazolyl)-2-(carboxymethoxyimino) acetamido]-3-vinyl-3-cephem-4-carboxylic acid (3, FK027) are described. Diphenylmethyl 7-amino-3-vinyl-3-cephem-4-carboxylate hydrochloride (8), the cephem precursor to FK027 was prepared from 7-aminocephalosporanic acid (7-ACA) by two parallel routes differing primarily in the protection of the 7-amino group. Compound 8 was alternatively prepared from deacetylcephalosporin C sodium salt (DCCNa) with improved yields. Two pathways for the conversion of 8 to FK027 are provided. The new orally active cephalosporin, FK027, possesses a widely expanded antimicrobial activity and high stability to beta-lactamases.     

头孢唑肟酸合成方法研究

目的 优化头孢唑肟酸合成条件.方法 考察四氢呋喃,乙酸乙酯,二氯甲烷,N,N-二甲基乙酰胺四种溶剂对7-氨基-3-去甲基-3-头孢烷酸(7-ANCA)与2-(2-氨基4-噻唑基-2-甲氧亚胺乙酸苯并噻唑硫酯(AE活性酯)合成头孢唑肟酸收率的影响.结果 确立了较优合成工艺条件:以乙酸乙酯为溶剂,n(7.ANCA):n(AE活酯):n(三乙胺)=1:1.2:2时,产品收率91.8%,纯度99.85%(HPLC),产品质量符合药典标准.结论 此方法简捷、易于产业化.     

Studies on beta-lactam antibiotics. III. Syntheses and antibacterial activities of new 3-(1,3-dithiolan-2-yl)cephalosporins, YM-22508, YM-16457 and their prodrug-type esters

The syntheses and biological activities of new 7-beta-[(Z)-2-(2-amino-4-thiazolyl)-2-hydroxy-iminoacetamido]-3-(1 ,3- dithiolan-2-yl)-3-cephem-4-carboxylic acid (YM-22508, 1a), 7-beta-[(Z)-2-(2-amino-4-thiazolyl)-2- methoxyiminoacetamido]-3-(1,3-dithiolan-2-yl)-3-cephem-4-carboxyli c acid (YM-16457, 1d) and their prodrug-type esters are described. Among them, YM-22561 (1c), the 1-acetoxyethyl ester of 1a, showed good in vivo efficacy in mice against infections of Staphylococcus aureus Smith, Streptococcus pyogenes S 23 and Escherichia coli NY-17 and a long plasma T1/2 in mice.     

Synthesis and antimicrobial activity of 7 alpha-methoxypyrimidinyl-ureidocephalosporins

The synthesis of a series of 7 alpha-methoxy-7-[(R)-2-[3-[5-pyrimidinyl]ureido]-2-(4-hydroxyphenyl) acetamido]-3-cephem-4-carboxylates 2 is described. 7-[(R)-2-[3-[2-(p-Aminosulfonyl)-anilino-4-hydroxy-5-pyrimidinyl]ureido- 2-(4-hydroxyphenyl)acetamido]-7 alpha-methoxy-3-[(1-methyl-1H-tetrazol-5 -yl)thio]methyl-3-cephem-4-carboxylic acid, sodium salt (2k, UG-FA 132), has exhibited a broad range of antimicrobial activity. UG-FA 132 is highly active against Gram-positive and Gram-negative organisms, including Pseudomonas and lactamase producers, and shows potent activity against anaerobes. The high efficacy of UG-FA 132 was confirmed by in vivo experiments in mice.     

Stereo-specific synthesis of 3-trifluoromethylcephalosporin derivative by microbial acylase.

Cephalosporin acylase (EC 3.5.1.11) obtained from Kluyvera citrophila ATCC 21285 was found to catalyze synthesis of 7-[2-(2-thienyl)acetamido]-3-trifluoromethyl-3-cephem-4-carboxylic acid from methyl thienylacetate and dl-7-amino-3-trifluoromethyl-3-cephem-4-carboxylic acid. The enzymatically-synthesized compound showed [alpha]25 D + 42.7 degrees (c 0.058, MeOH) and its biological activity was about twice as much as that of racemic 7-[2-(2-thienyl)acetamidol]-3-trifluoromethyl-3-cephem-4-carboxylic acid chemicall synthesized. As a result, N-acylation by this enzyme was demonstrated to be asymmetric synthesis.     

Studies on beta-lactam antibiotics VIII. Structure-activity relationships of 7 beta-[(Z)-2-carboxymethoxyimino-2-arylacetamido]-3-cephem- 4-carboxylic acids

The synthesis, antimicrobial activity and oral absorptivity of 7 beta-[(Z)-2-carboxymethoxyimino-2-arylacetamido]-3-cephem-4- carboxylic acids are described. The [(Z)-2-(2-amino-4-thiazolyl)-2-carboxymethoxyimino]acetyl group was selected as the most suitable 7-substituent from seven 7-acyl groups for our further investigation of orally active cephalosporins.     

头孢硫脒新杂质的制备及结构解析

目的 对头孢硫脒的氧化杂质和双键转移杂质进行制备和结构分析。方法 用适当的反应方法处理原料，目标杂质用HPLC定位，经分离纯化得到两个杂质的纯品，通过多级质谱和核磁共振确认其结构。结果 对制备得到的两个杂质的结构做了解析，双键转移杂质为6R,7R-3-[(乙酰氧基)甲基)]-7-[α-N,N'-二异丙基脒硫基)乙酰氨基]-8-氧代-5-硫杂-1-氮杂双环[4.2.0]辛-3-烯-2-甲酸内铵盐，氧化杂质为6R,7R-3-[(乙酰氧基)甲基)]-7-[α-(N,N›-二异丙基脒硫基)乙酰氨基]-8-氧代-5-硫杂-1-氮杂双环[4.2.0]辛-2-烯-2-甲酸内铵盐-5-氧化物，并推测出其降解路线。结论 本研究对头孢硫脒原料及其制剂的杂质分析和质量控制有重要参考价值。     

AS-924, a novel bifunctional prodrug of ceftizoxime.

To improve the oral absorption of ceftizoxime (CZX), 7beta-[(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]- 3-cephem-4- carboxylic acid, we synthesized and evaluated a novel series of bifunctional prodrugs, in which L-alanine was introduced into the aminothiazole-oxime moiety at the C-7 position of the various lipophilic esters of CZX. Among these prodrugs, pivaloyloxymethyl 7beta-[(Z)-2-(2-(S)-alanylaminothiazol-4-yl)-2-methoxyiminoa cetamido]-3-cephem-4-carboxylate hydrochloride (ceftizoxime alapivoxil, AS-924) was well absorbed after oral administration in experimental animals and showed potent therapeutic effects in mice infected with gram-positive and gram-negative bacteria.     

3-Quaternary ammonium 1-carba-1-dethiacephems

A series of structurally unique 1-carba-1-dethiacephems is described. The structural stability of the 1-carba-1-dethiacephem nucleus was essential for the preparation of this series of 3-quaternary ammonium carbacephems. The known p-nitrobenzyl 7 beta-(phenoxyacetamido)- 3-[(trifluoromethyl)sulfonyl]oxy]-1-carba-1-dethia-3-cephem- 4-carboxylate served as both a quaternization substrate as well as a precursor to derivatives such as allyl 7 beta-[[2-[allyloxy)carbonyl]amino-4- thiazoly] (methoxyimino)acetyl]amino]-3-[(trifluoromethyl) sulfonyl] oxy]-1-carba-1-dethia-3-cephem-4-carboxylate. Quaternization of these enol triflates was accomplished either by dissolution in acetonitrile containing the base or by dissolution in the base, with or without warning to 50 degrees C. Bases nucleophilic enough to displace the triflate include a variety of substituted pyridines and N-methylimidazole. Deprotection then produced a very active series of 1-[7 beta-[(2-amino- 4-thiazolyl)(methoxyimino)acetyl]amino]-2-carboxy-8-oxo- 1-azabicyclo[4.2.0]oct-2-en-3-yl] quaternary ammonium hydroxide inner salts. These compounds were extremely potent antibacterials against a broad range of Gram-positive and -negative bacteria including constitutive cephalosporinase producers, such as Enterobacter cloacae. The compounds exhibit similar hydrolysis kinetics and pharmacokinetics to the analogous cephalosporin-3'-quaternary ammonium salts.     

Isolation, structural elucidation and characterization of impurities in Cefdinir

Three unknown impurities in Cefdinir bulk drug at levels below 0.2% (ranging from 0.05 to 0.2%) have been detected by high performance liquid chromatography (HPLC). These impurities were isolated from crude sample of Cefdinir using preparative HPLC. Based on the spectral data (NMR, IR and MS) the structures of these impurities were characterized as (6R, 7R)-7-[(z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-8-oxo-3-vinyl-5-thia-1-azabicyclo [4.2.0] oct-2-ene-2-carboxylic acid-5-oxide (I). (6R, 7R)-7-[(z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-8-oxo-3-vinyl-5-thia-1-azabi-cyclo [4.2.0] oct-3-ene-2-carboxylic acid (II). (6R, 7R)-7-[(z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-8-oxo-3-methyl-5-thia-1-azabicyclo-[4.2.0]oct-2-ene-2-carboxylic acid (III), respectively. The origin and structural elucidation of all impurities have been discussed.     

Synthesis and structure-activity relationships of 3-(2-imidazolyl)thiomethyl cephalosporins

The synthesis and structure-activity relationships of a series of 3-(2-imidazolyl)thiomethyl cephalosporins are described. Among the compounds, 7 beta-[2-(2-amino-1,3-thiazol-4-yl)-(Z)-2-methoxyiminoacetamido]-3- [(4,5-dicarboxyimidazol-2-yl)thiomethyl]-3-cephem-4-carboxylic acid (1) exhibited potent activity against both Gram-positive and Gram-negative bacteria including Pseudomonas aeruginosa. We also estimated lipophilicity of the compounds from the chromatographic log k' value of reversed-phase HPLC. The relationship between lipophilicity and biological activity showed that compound 1 had the most suitable lipophilicity.     

Synthesis and structure-activity relationships of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]cephalosporin derivatives. V. Synthesis and antibacterial activity of 7 beta-[2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-cephalosporin derivates and related compounds

In order to improve the antibacterial activity of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]-cephalosporins new derivatives having a methoxyimino moiety in the 7-acyl side chain and related compounds were synthesized. Of these, 7 beta-[2-(2-aminothiazol-4-yl)-(Z)-2-methoxyiminoacetamido]-cephalosporins were found to possess excellent activity against a variety of Gram-positive and Gram-negative bacteria including beta-lactamase-producing strains. An extensive study of structure-activity relationships led to the selection of 7 beta-[2-(2-aminothiazol-4-yl)-(Z)-2-methoxyiminoacetamido]-3-[(1-methyl-1H-tetrazol-5-yl) thiomethyl]-ceph-3-em-4-carboxylic acid, SCE-1365, for further biological and clinical evaluation.     

Synthetic cephalosporins. II. The synthesis and oral activity of 7-[R-2-amino-2-(3-chloro-4-hydroxyphenyl)acetamido]-3-methylthio-3- cephem-4-carboxylic acid and related compounds

A series of 3-methylthio-3-cephem-4-carboxylic acids were prepared to test their antibacterial activities, and 7-[R-2-amino-2-(3-chloro-4-hydroxyphenyl)acetamido]-3-methylthio-3-ce phe m-4- carboxylic acid was found to be a new orally active antibiotic.     

Synthetic cephalosporins. V. Synthesis and antibacterial activity of 3-alkylthio-7 beta-[(Z)-2-(2-aminothiazol-4-yl)-2-(O-substituted oxyimino)acetamido]cephalosporins and related compounds

3-Alkylthio-7 beta-[(Z)-2-(2-aminothiazol-4-yl)-2-(O-substituted oxyimino)acetamido]cephalosporins (6 and 7) and the 3-methoxy analogues (10) were prepared by coupling diphenylmethyl 7-amino-3-alkylthio-3-cephem-4-carboxylate (1 and 2) or diphenylmethyl 7-amino-3-methoxy-3-cephem-4-carboxylate with (Z)-2-(2-tritylaminothiazol-4-yl)-2-(O-substituted oxyimino)acetic acid (4), followed by deprotection and subjected to examination of antibacterial activities. The pivaloyloxymethyl esters (8 and 9) of the compounds (6 and 7) were also prepared and oral activities of these esters were compared with those of the parent compounds (6 and 7). The cephalosporins (6a-j and 7a-c) had potent and wide antibacterial spectra against Gram positive and Gram negative bacteria which were comparable to those of cefixime or cefteram. Among them, the cephalosporins (6f and 7c) and the pivaloyloxymethyl esters (8b and 9b) had good in vivo efficacy in mice against infections of Escherichia coli No. 29 and especially 8b showed high urinary recovery in mice.     

Impurity profile study of zaleplon

Zaleplon is a pyrazolopyrimidine derivative and possesses sedative and hypnotic properties. Seven unknown impurities in zaleplon bulk drug at levels below 0.1% were detected by reverse-phase high performance liquid chromatography (HPLC). The starting material, 3-amino-4-cyanopyrazole and an intermediate, N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]-phenyl]-N-ethylacetamide (DOPEA) were also present in the sample at a level below 0.1%. The molecular weights of impurities were determined by LC-MS analysis. These impurities were isolated from crude samples of zaleplon using reverse-phase preparative HPLC. Based on the spectral data the structures of these impurities were characterized as, N-(3-(3-(4-amino-2H-pyrazolo [3,4-d]pyrimidin-6-yl) pyrazolo[1,5-a] pyrimidin-7-yl)phenyl)-N-ethylacetamide (impurity I); N-[3-(3-carboxamidopyrazolo[1,5-a]pyrimidin-7-yl)phenyl]-N-ethylacetamide (impurity II); N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-7-yl)phenyl]acetamide (impurity III); N-[3-(3-cyanopyrazolo [1,5-a]pyrimidin-7-yl)phenyl]-N-methylacetamide (impurity IV); N-[3-(3-cyanopyrazolo[1,5-a] pyrimidin-5-yl)phenyl]-N-ethylacetamide (impurity V); N-[3-(3-cyanopyrazolo[1,5-a] pyrimidin-7-yl)phenyl]-N-ethylamine (impurity VI); N-[3-(3-cyano-6-[(E)-3-((N-ethyl-N-acetyl)amino)phenyl-3-oxoprop-1-enyl] pyrazolo[1,5-a]pyrimidin-7-yl) phenyl]-N-ethylacetamide (impurity VII). Structural elucidation of all impurities by spectral data ((1)H NMR, (13)C NMR, MS and IR) and formation of these impurities are discussed in detail.     

Synthesis and biological activity of substituted [[3(S)-(acylamino)-2-oxo-1-azetidinyl]oxy]acetic acids. A new class of heteroatom-activated beta-lactam antibiotics

The synthesis of substituted [[3(S)-(acylamino)-2-oxo-1-azetidinyl]oxy]acetic acids (1) is described. 3-[(Carbobenzyloxy)amino]-N-hydroxy-2-azetidinones (13a,b), prepared from serine and threonine, were alkylated with 2-(trimethylsilyl)ethyl bromoacetate in the presence of potassium carbonate in THF/H2O. Alkylation with secondary alpha-bromo esters was accomplished with potassium hydroxide in dimethyl sulfoxide. The Cbz group was replaced with the 2-(2-amino-4-thiazolyl)-2(Z)-(methoxyimino)acetamido side chain by catalytic hydrogenation followed by treatment with 21. Removal of the 2-(trimethylsilyl)ethyl ester with fluoride ion provided derivatives suitable for antimicrobial evaluation. In vitro tests showed that the title compounds possess significant activity predominantly against Gram-negative bacteria.     

The comparative stability of different types of penicillin and cephalosporin N-pyrryl derivatives

The kinetics of the decomposition of potassium salts of 4-thia-1-azabicyclo[3.2.0.]heptane-3,3-dimethyl-6-amino-7-oxo-N- [2(1H-pyrrolyl)acetyl] -2-carboxylic acid (6R, trans), 4-thia-1-azabicyclo[3.2.0]heptane-3,3-dimethyl-6-amino-7-oxo-N-[2-phenyl - 2(1H-pyrrolyl)acetyl]-2-carboxylic acid (6R, trans), 5-thia-1-azabicyclo[4.2.0.]oct-2-ene-3- [(acetyloxy)methyl]-7-amino-8-oxo-N-[2(1H-pyrrolyl)acetyl]-2-ca rbo xylic acid (6R, trans), 5-thia-1-azabicyclo[4.2.0.]oct-2-ene-3- [(acetyloxy)methyl]-7-amino-8-oxo-N-[2-phenyl-2(1H-pyrrolyl)acetyl ]- 2-carboxylic acid (6R, trans), 5-thia-1-azabicyclo[4.2.0.]oct-2-ene-7-amino-3-methyl-8-oxo-N- [2(1H-pyrrolyl)-acetyl]-2-carboxylic acid (6R, trans) and 5-thia-1-azabicyclo[4.2.0.]oct-2-ene-7-amino-3-methyl-8-oxo- N-[2-phenyl-2(1H-pyrrolyl)acetyl]-2-carboxylic acid (6R, trans), in aqueous solution at 37 degrees C and at ionic strength of 0.5 mol.l-1 have been studied over the 2.3-11.5 pH range. In all cases, the hydrolysis of these compounds is subject to acid-base catalysis and, in some instances, to a general catalysis by various species present in the buffer solutions. The experimental results have been analyzed and discussed in relation to the hydrolytic mechanisms.     

Improved synthesis of an ester-type prodrug, 1-acetoxyethyl 7-[(Z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-[(Z)-1- propenyl]-3-cephem-4-carboxylate (BMY-28271)

1-Acetoxyethyl 7-[(Z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3- [(Z)-1-propenyl]-3-cephem-4-carboxylate (BMY-28271) is an ester-type prodrug of cephalosporin for oral use. Methods suitable for large scale preparation were investigated. The yield was improved by esterification of 7-[(Z)-2-(2-aminothiazol-4-yl)-2-trityloxyiminoacetamido]cep hem-4-carboxylic acid (11) followed by removal of the trityl group and, in addition, column chromatographic purification at each step was eliminated by optimization of the reaction conditions.