60845-81-0Relevant articles and documents
Synthetic method for ethyl 2-(2-aminothiazol-4-yl)-2-methoxyiminoacetate
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Paragraph 0016; 0017, (2020/01/12)
The invention discloses a synthetic method for ethyl 2-(2-aminothiazol-4-yl)-2-methoxyiminoacetate. The method is characterized by comprising the following steps: a, performing chlorination on diketene, and performing alcoholysis to synthesize ethyl 4-chloroacetoacetate; b, performing oximation on the ethyl 4-chloroacetoacetate to synthesize ethyl 4-chloro-2-(hydroxyimino)-3-oxobutanoate; c, performing a reaction on the ethyl 4-chloro-2-(hydroxyimino)-3-oxobutanoate and thiourea to synthesize ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate; and d, performing hydrocarbonylation on the ethyl2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate to synthesize the ethyl 2-(2-aminothiazol-4-yl)-2-methoxyiminoacetate. The method has the following advantages: 1, the chlorination reaction in the stepa is a continuous reaction, and has a fast reaction speed and no accumulation of a large amount of dangerous materials, so that the danger is small; 2, the costs of equipment are lower, the equipmentis conventional organic synthesis equipment, no expensive and special equipment is needed, so that the equipment is easy to copy, and the production efficiency is improved; and 3, the diketene is directly used as a raw material, the raw material cost is low, the synthetic steps are simple to operate, so that the method facilitates reducing the production costs of the ethyl 2-(2-aminothiazol-4-yl)-2-methoxyiminoacetate.
One-pot ceftazidime side-chain acid ethyl ester synthesis method
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, (2016/12/16)
The invention relates to a preparation method of a pharmaceutical intermediate, in particular to a one-pot ceftazidime side-chain acid ethyl ester synthesis method. The method comprises the following steps that 1, ethyl 4-bromoacetoacetate is dissolved in water, a sodium nitrite water solution and 15%-25% of sulfuric acid are added dropwise, heat preservation reaction is performed after adding is completed dropwise, extraction is performed after the reaction is completed, the extracting solution is washed with a saturated potassium or sodium carbonate solution, and distillation is performed to obtain an oximation solution; 2, thiourea is added into a water and methanol mixed solution, and then the oximation solution is added dropwise to obtain an ethyl 2-(2-aminothiazole-4-yl)-2-hydroxyiminoacetate solution; 3, the pH of the ethyl 2-(2-aminothiazole-4-yl)-2-hydroxyiminoacetate solution is regulated, then tert-butyl alpha-bromoisobutyrate and a phase transfer catalyst are added for heat preservation reaction, and after the reaction is completed, cooling and suction filter are performed to obtain the ceftazidime side-chain acid ethyl ester. The simple processing of the product is simple, the purity and the yield are high, and the yield is up to 96.5% or above.
Thiazolylacetamido cephalosporin type compounds
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, (2008/06/13)
Novel cephem compounds of the formula; STR1 wherein R1 represents amino or hydroxyl group which may be protected, R2 represents amino or hydroxyl group or a group convertible into these groups, R3 represents hydrogen or methoxy group or a group convertible into methoxy group, R4 represents hydrogen or a residue of a nucleophilic compound and R8 represents hydrogen or a halogen, or a pharmaceutically acceptable salt or ester thereof, have strong antibiotic properties against a wide variety of microorganisms including gram-positive bacteria as well as gram-negative ones, especially by oral administration and can be used as therapeutic agent for various bacterial infections of animals including human beings.
