- Translactonization of erythromycin a during oximation: Mixture analysis and reaction monitoring by NMR
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Oximation of erythromycin A with hydroxylamine hydrochloride and sodium acetate in methanol led to the formation of pseudoerythromycin A enol ether with erythromycin A oxime as analysed by detailed two-dimensional NMR spectroscopy in the mixture along with traces of 8,9-anhydroerythromycin A 6,9-hemiketal and erythromycin A 6,9:9,12-spiroketal. The formation of the degraded products was established by performing in situ 13C NMR spectroscopy. The analysis suggests that pseudoerythromycin A enol ether is formed by the translactonization of erythromycin A enol ether which forms as a result of acid degradation. Copyright
- Grover, Rajesh K.,Joshi,Batra,Roy, Raja,Bhaduri
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- Synthesis and antimicrobial activity of erythromycin-A oxime analogs
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A series of erythromycin-A oxime ether as well as esters have been synthesized. Ether derivatives were synthesized through the epoxy ether intermediate of erythromycin-9-oxime, followed by opening of the epoxy linkage through various amines, whereas esters have been prepared through DCC mediated protocol. These derivatives have been evaluated for antibacterial activity and found to be as active as erythromycin-A.
- Pandey, Deepa,Katti,Haq,Tripathi
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- Synthesis of two and antibacterial activity of one novel oxime ether derivatives of erythromycin A
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The synthesis of novel erythromycin A 9-O-(2-ethenesulfony-ethyl)-oxime and erythromycin A 9-O-(3-oxo-butyl)-oxime from erythromycin A (EA) by the Michael reaction is described and to describe the effects of transformation of ketone in position 9 of EA to an oxime ether. This transformation occurred in a single step without protecting of any functional moiety of erythromycin oxime and zero waste manner in good yield. The antibacterial screen of EA 9-O-(2-ethenesulfony-ethyl)-oxime is also reported.
- Dondas,Yaktubay
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- Method for synthesizing azorithromycin by utilizing erythromycin thiocyanate oxime
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The invention relates to a method for synthesizing azithromycin by utilizing erythromycin thiocyanate oxime. The method comprises the following process steps: removing thiocyanate radicals through erythromycin thiocyanate oxime dissociation, performing rearrangement reaction, performing continuous back extraction, performing continuous reduction reaction and separation, and performing azithromycin crystallizing. According to the invention, the thiocyanate radicals are removed before the rearrangement reaction and then the rearrangement is performed, the reduction reaction adopts a continuous reaction process, the reaction mode is changed, and the process is high in reaction efficiency, low in production cost, small in environmental pollution, high in product yield and good in product quality.
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Paragraph 0037-0038; 0044-0045; 0051-0052
(2021/05/05)
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- Synthetic method of isotope-labeled erythromycylamine
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The invention discloses a synthetic method of isotope-labeled erythromycylamine, belongs to the field of drug metabolism, and provides a synthetic method which is reasonable in process design, strongin operability and high in yield, can efficiently convert isotope-labeled raw materials into labeled target products, and can realize industrial production of isotope-labeled erythromycylamine. The method takes 13CD3 labeled methyl iodide as a starting raw material, the isotope-labeled erythromycylamine is synthesized by six steps of reactions, optimal preparation steps and reaction conditions arescreened out through a large number of experiments, the whole process is reasonable in design and high in operability, the labeled raw materials can be efficiently converted into labeled target products, the chemical purity of the labeled erythromycylamine prepared through the method can reach 98.5% or above, and the labeled isotope abundance is larger than 98.5%.
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Paragraph 0020; 0025-0027; 0033-0035; 0041-0043
(2020/07/28)
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- Preparation method of erythromycin A oxime
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The invention belongs to the technical field of medical chemistry and particularly relates to a preparation method of erythromycin A oxime. The method has the advantages of being simple in operation, high in yield and good in product purity and suitable for large-scale industrial production.
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Page/Page column 5
(2017/08/31)
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- Macrolide derivative and application thereof
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The invention provides a macrolide derivative of a novel structure. Experiments show that the macrolide derivative has a good promoting effect on alimentary motility and is capable of enhancing intestine peristalsis, increasing defecation quantity and accelerating passing of intestinal content; on such basis, it is further discovered that the macrolide derivative is low in antibiotic activity and small in side effect and can be taken as a gastrointestinal motility promoting drug. Particularly, a compound III-3 screened with the optimal efficacy is subjected to further efficacy evaluation as well as acute toxicity and cardiotoxicity evaluation by domestic rabbits, beagles and marmosets. Experiments show that the compound III-3 is safe and capable of effectively promoting gastrointestinal motility, thereby being excellent in druggability.
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Paragraph 0022; 0045
(2017/08/28)
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- Method for synthesizing azithromycin
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The invention relates to a method for synthesizing azithromycin. According to the invention, erythromycin thiocyanate is adopted as an initial raw material of an oximation reaction, such that erythromycin oxime thiocyanate is obtained; the next step of reaction is directly carried out; and through rearrangement, reduction and methylation reactions, azithromycin is obtained. The rearrangement and reduction reactions are carried out with a one-pot method. A reduction reaction product is not separated in a solid form, and is directly used in the methylation reaction. With the synthesizing method provided by the invention, a conversion process from erythromycin oxime thiocyanate to eythromycin oxime is eliminated, and steps that rearrangement and reduction products are separated in solid forms in an original process are also eliminated. The process is environment-friendly and simple, and has the advantages of high yield, low cost, low pollution and high product purity. The method is suitable for industrialized productions.
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Paragraph 0012; 0031; 0032; 0033
(2016/11/17)
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- PROCESSES FOR PREPARING MACROLIDES AND KETOLIDES AND INTERMEDIATES THEREFOR
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The invention described herein pertains to processes for the preparation of macrolide antibacterial agents. In particular, the invention pertains to processes for preparing macrolides and ketolides from erythromycin A.
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Paragraph 0074
(2015/09/22)
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- Process for the preparation of clarithromycin
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The present invention includes a process involving a one-pot reaction for preparing erythromycin 9-oxime salt comprising: (a) reacting erythromycin thiocyanate with an ammonium source to obtain erythromycin free base; (b) oximating the C-9 carbonyl of the erythromycin free base by reacting the erythromycin free base with triethylamine and hydroxyl amine hydrochloride to form erythromycin oxime; and (c) reacting the erythromycin oxime obtained in step (b) with an ammonium source to obtain the erythromycin 9-oxime salt. The present invention is also drawn to a one-pot reaction for preparing clarithromycin starting with the one-pot reaction for preparing erythromycin 9-oxime salt, further comprising after step (c): (d) silylating the hydroxy groups at the oxime group, and the 2′ and 4″ positions of the erythromycin 9-oxime salt to obtain a silylated derivative; (e) methylating the hydroxy group at the 6 position of the silylated derivative using at least one methylating agent in the presence of at least one inorganic base to obtain SMOP, wherein SMOP is 6-O-methyl-2′,4″-bis(trimethylsilyl)-erythromycin A 9-O-(2-methoxyprop-2-yl)oxime; and (f) converting the SMOP into clarithromycin using at least one deoximating agent in the presence of aqueous ethanol.
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(2009/04/24)
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- PROCESS FOR THE PREPARATION OF FORM II CLARITHROMYCIN
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The present invention provides an efficient process for the preparation of polymorphic Form I and II of clarithromycin. The process includes drying wet clarithromycin obtained after purification in the presence of nitrogen gas and in the absence of vacuum. The invention also relates to pharmaceutical compositions that include the Form II of clarithromycin and use of said compositions for treating a condition for which antibiotics are indicated.
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Page/Page column 6
(2008/06/13)
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- Synthesis and bioactivity of erythromycin derivatives
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A small series of semi-synthetic 6-O-alkylated erythro mycin derivatives were synthesized and evaluated for their antimicrobial activity. A dichlorobenzenyl 6-O-allyl erythromycin derivative, 11a was found to be active against Cryptococcus neoformans (IC50 5.0 μg/mL), Staphylococcus aureus (IC50 5.0 μg/mL), and methicillin-resistant Staphlococcus aureus (IC50 5.0 μg/mL).
- Chen, Mingwei,Muri, Estela M. F.,Jacob, Melissa,Williamson, John S.
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p. 111 - 129
(2007/10/03)
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