- Antibiotic-improved cefmenoxime hydrochloride synthesis process
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The invention discloses an antibiotic-improved cefmenoxime hydrochloride synthesis process, which comprises the following steps: step 1, preparation of 1-methyl-5-sulfydryl-1H-tetrazole, step 2, preparation of 2-(2-amino-4-azolyl)-2(Z)-methoxyimino ethyl acetate; step 3, preparation of 2-(2-amino-4-thiazolyl)-2-(Z)-methoxyimino acetic acid; step 4, preparation of 2-(2-amino-4-thiazolyl)-2-(Z)-methoxyimino acetic acid-2-benzothiazole thioester; step 5, preparation of 7-amino-3-(1-methyl-1H-tetrazole-5-thiomethyl)cephalosporanic acid hydrochloride (7-ACA-MMT. HC1); and step 6, preparation of cefmenoxime hydrochloride; domestic raw materials are adopted, the raw materials are cheap and easy to obtain in the synthesis route, the synthesis cost is reduced, and synthesis is improved; the improved process has the advantages of low raw material cost, simplicity in operation and suitability for industrial production.
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Paragraph 0045
(2021/02/06)
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- Clean preparation process of aminothiazoly loximic acid
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The invention discloses a clean preparation process of aminothiazoly loximic acid, and belongs to the technical field of organic synthesis. The method comprises the following steps: (1) dropwise adding sulfuric acid into ethyl acetoacetate and calcium nitrite for oximation, separating out a calcium sulfate solid, filtering and washing wet calcium sulfate powder to obtain calcium sulfate, adding sodium carbonate into a washing solution and filtrate, and dropwise adding dimethyl sulfate for methylation of oxime; (2) after completion of the cyclization reaction, carrying out phase splitting, dehydrating an organic phase, then carrying out halogenation, adding water for quenching, carrying out phase splitting, taking strongly acidic water as a water phase and a halide as an organic phase, dropwise adding the halide into thiourea, carrying out a cyclization reaction, adding trichloromethane after completion of the cyclization reaction, and carrying out phase splitting to remove the water phase so as to obtain an ethyl aminothiazoxylate trichloromethane solution; and (3) dropwise adding liquid caustic soda, hydrolyzing, carrying out phase splitting after the reaction is finished, removing the organic phase, decolorizing the water phase, and dropwise adding the quenched water phase until the aminothiazoly loximic acid is completely separated out. The method produces less three wastes, can realize resource recycling, and is high in product yield, simple to operate and easy to realize.
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Paragraph 0030; 0033-0034; 0037-0038; 0041
(2021/04/17)
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- Process for producing chloroacetylaminothiazoleacetic acid derivatives
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The present invention relates to a simple process for producing 2-aminothiazoleacetic acid derivatives useful as intermediates for producing cephalosporin-type antibiotics. The process for producing chloroacetylaminothiazoleacetic acid derivatives represented by the following formula (II) ???wherein R1 is a protection group for the hydroxyl group,comprises reacting aminothiazoleacetic acid derivatives represented by the following formula (I) ???wherein R1 is a protection group for the hydroxyl group,with a chloroacetylating agent.
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- Scope and Mechanism of Deprotection of Carboxylic Esters by Bis(tributyltin) Oxide
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Methyl and ethyl esters of aliphatic and aromatic carboxylic acids as well as benzyl carboxylates, thiol esters and double esters such as (pivaloyloxy)methyl carboxylates have been successfully cleaved with bis(tributyltin) oxide to give the free carboxylic acids in good yields.The reaction is carried out in aprotic solvents under essentially neutral conditions and thus this method can serve as an ideal procedure for the cleavages of esters with other functional groups and/or protecting groups acid and/or base sensitive.We demonstrated that the reaction displays a high level of chemoselectivity between methyl and ethyl esters versus tert-butyl esters and γ-lactones.Bis(tributyltin) oxide is also a highly efficient reagent for the cleavage of acetates of primary and secondary alcohols and phenols.The limitations we found in the use of this reagent include the lack of cleavage of esters sterically hindered around the carboxyl carbon and the carbinol group (i.e., esters of tertiary alcohols) and in carboxylic esters that contain a fluoroalkyl substituent.A resonable mechanistic explanation is discussed to account for the reaction pathway of the acyloxygen cleavage of (-)-(1R)-menthyl acetate.
- Salomon, Claudio J.,Mata, Ernesto G.,Mascaretti, Oreste A.
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p. 7259 - 7266
(2007/10/02)
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- Triazolo-pyrimidine intermediates
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There are disclosed a β-lactam compound represented by the formula (I): STR1 wherein R1 represents an acyl group; M represents a hydrogen atom, a protective group of an eliminatable group which is easily hydrolyzable in a human body; B represents a group represented by the formula (b): STR2 where at least one of R2, R3 and R9 represent a group represented by the formula: -A-OR4 where R4 represents a hydrogen or a lower alkyl group; and A represents a straight or branched alkylene group having 1 to 6 carbon atoms; and a remaining group or groups are each independently a hydrogen atom; a cyano group; a lower alkyl group which may be substituted by a halogen atom; a carbamoyl group which may be substituted by a lower alkyl group; a cycloalkyl group; or a carboxyl group which may be substituted by a protective group of an eliminatable group which is easily hydrolyzable in a human body, and also when R9 is -A-OR4, R2 and R3 may be combined with each other to form an alkylene group having 3 to 4 carbon atoms; and Z represents a nitrogen atom or a group represented by the formula: C-R10 where R10 represents a hydrogen atom, a carboxyl group or a lower alkyl group which may be substituted by a hydroxy group or a lower alkoxy group, or its pharmaceutically acceptable salt, and a process for preparing the same, an intermediate for synthesis of the same and a medicinal composition for bacterially infectious disease therapy containing the same.
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- Processes for preparing 3-cephem compounds
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This invention relates to novel compounds of antimicrobial activity of the formula: STR1 wherein R1 is an aliphatic hydrocarbon group which may have suitable substituents, R2 is carboxy or protected carboxy, R5 is hydrogen or hydroxy, X1 and X2 are each halogen, and the dotted line represents cepham or cephem nucleus, or a salt thereof.
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- 7-Thiazolyl-acetamido-cephem derivatives with terminal aminocarboxylic acid grouping
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The invention relates to aminothiazolacetamido-3-cephem-4-carboxylic acid compounds of the formula STR1 in which the index n represents an integer of 1 to 4, X represents oxygen, sulphur, an --NH-- group or the direct bond, Y represents oxygen or sulphur, A represents methylene or methylene substituted by amino, hydroxy, carboxyl, sulpho, oxo, or the group =N--O--Ro in which Ro represents hydrogen or optionally substituted lower alkyl, R1 represents hydrogen, lower alkyl, an esterified or etherified hydroxy or mercapto group, halogen, formyl or a group of the formula --CH2 --R2 in which R2 represents an esterified or etherified hydroxy or mercapto group or a quaternary ammonium group, and R3 represents hydrogen or methoxy, in which functional groups are optionally present in protected form, salts of such compounds with acidic and/or basic groups, processes for the manufacture of these compounds, pharmaceutical agents containing such substances and their therapeutic use. The compounds have an antibiotic activity and can be used for combating infections. The invention also relates to new intermediates for the manufacture of the afore-mentioned compounds, processes for their manufacture and their use.
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- Method for removing protective groups
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A halogenoacetyl group is removed from a halogenoacetyl amino compound in a short period of reaction time by reacting the halogenoacetyl amino compound with an N-substituted dithiocarbamic acid or a salt thereof.
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