- Preparation method of AE-active ester
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The invention relates to the technical field of medicinal chemistry, in particular to a preparation method of AE-active ester. The method comprises the following steps: dissolving aminothiazoly loximic acid in an organic solvent, adding triethylamine under the action of a catalyst, carrying out a thermal insulation reaction, adding dibenzothiazyl disulfide and triethyl phosphite, and carrying outa stirring reaction to obtain the AEactive ester. The AE active ester obtained by the method is good in clarity and less in free acid; the crystal is more regular in shape and more transparent in color, the purity and stability of the product are improved, and the yield is also obviously improved. The yield of the AE-active ester is up to 92.7% or above, and the purity of the AE-active ester is 99.5% or above.
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Paragraph 0035-0055
(2021/03/13)
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- Synthesis process of AE-active ester
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The invention belongs to the technical field of medicines, and particularly relates to a synthesis process of AE-active ester. The preparation method comprises the following steps: adding 2-(2-aminothiazole-4-yl)-2-methoxyiminoacetic acid and a phase transfer catalyst into an organic solvent, adding dicyclohexylcarbodiimide, and stirring to obtain a solution A; adding 2-mercaptobenzothiazole intothe organic solvent, and stirring and dissolving to obtain a solution B; adding the solution B into the solution A, reacting, and filtering to obtain a filtrate; and carrying out reduced pressure distillation on the filtrate, cooling to 10 DEG C or below, carrying out suction filtration, leaching with the organic solvent, and drying to obtain the AE-active ester. The method avoids the generation of phosphorus-containing waste residues and wastewater and the use of highly toxic raw material chloroformate in the traditional process, has the advantages of simple process, low cost, greenness and environment friendliness, is easy for industrial production, and has extremely high industrial application value.
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Paragraph 0039; 0041-0048; 0050-0057; 0059-0065
(2020/08/30)
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- Preparation process for 2-(2-amino-4-thiazolyl)-2-methoxyiminoacetic, thiobenzothiazole ester
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The invention discloses a preparation process for 2-(2-amino-4-thiazolyl)-2-methoxyiminoacetic, thiobenzothiazole ester. The process uses 2-(2-aminothiazole-4-yl)-2-methoxyiminoacetic acid as a starting raw material, amino is protected by using an organic solvent solution of HCl, the obtained material and an acylating chlorination reagent are subjected to a reaction in the presence of DMF to prepare 2-(2-aminothiazole-4-yl)-2-methoxyiminoacetic acid acyl chloride hydrochloride, crystallization is not performed, reduced-pressure distillation is performed under at a certain temperature to removean excess acylating chlorination reagent, a mixed liquid of dichloromethane and acetonitrile is added for dissolving, and a mixed liquid of 2-mercaptobenzothiazole and an acid binding agent is directly added to prepare the 2-(2-amino-4-thiazolyl)-2-methoxyiminoacetic, thiobenzothiazole ester. The process provided by the invention has the advantages of a high utilization rate of groups, fewer by-products, cleanness, environmental protection, good product quality and the like.
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Paragraph 0019; 0021; 0024; 0025
(2018/07/30)
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- Green method for synthesizing AE-active ester through microwave-assisted process
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The invention belongs to the technical field of synthesis of medicines and particularly relates to a green method for synthesizing AE-active ester through a microwave-assisted process. The green method for synthesizing AE-active ester through the microwave-assisted process comprises the following steps: firstly adding 2-(2-aminothiazole-4-yl)-2-methoxyiminoacetic acid, dithiodibenzothiazole, catalyst and solvent into a microwave reactor, then dropwise adding triethyl phosphate into the microwave reactor, reacting, carrying out suction filtration and recrystallization to obtain a product. The synthesis method is simple to operate and low in cost; the productivity can be greatly improved; the yield is increased and reaches up to 95%; the purity of the product is relatively high and reaches over 99%; the pleasantly surprised technical effect can be obtained.
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Paragraph 0030-0038
(2019/01/10)
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- Method for synthesizing AE active ester
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The invention discloses a method for synthesizing AE active ester. The AE active ester is prepared by a condensation reaction of 2-amino-alpha-(methoxyimino)-4-thiazoleacetic acid and 2-mercaptobenzothiazole used as raw materials in the presence of a condensation reagent, an organic alkali and an organic solvent, wherein the condensation reagent used in the reaction is chloroformate, the organic alkali is triethylamine, pyridine, N-methylmorpholine or DMAP, and the solvent is dichloromethane, acetonitrile or a mixed solvent of dichloromethane and acetonitrile. The method for synthesizing AE active ester avoids organic phosphorus condensation reagents used in traditional processes, achieves the discharge of non-phosphorus sewage, and greatly reduces the environmental protection pressure tomake enterprises achieve sustainable development. Additionally, the solvent can be recovered and recycled, so the production cost is greatly reduced, and the method has great implementation values.
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Paragraph 0028; 0029
(2018/11/27)
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- Method for synthesizing AE active ester by ester exchange method
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The invention discloses a method for synthesizing AE active ester by an ester exchange method. According to the method, ethyl 2-2-methoxyiminoacetate and 2-mercaptobenzothiazole are used as raw materials for preparing the AE active ester under the existence condition of organic solvents through the organic alkali catalysis ester exchange. The ethyl 2-2-methoxyiminoacetate compounds used in the reaction are methyl ester, ethyl ester, isopropyl ester or tert-butyl ester and the like; the used catalysts are organic amine compounds; the reaction solvents are aromatic hydrocarbon solvents such as methylbenzene, o-xylene and nitrobenzene. The method for synthesizing AE active ester has the advantages that the process is simple; the yield is good, and is about 83 to 88 percent; the organic phosphorus condensation reagent used in a conventional process is avoided; the phosphorus sewage discharge avoidance is reached; the environment-friendly pressure is greatly reduced; enterprises can realizethe sustainable development. In addition, the solvents can be recovered for cyclic utilization; the production cost is greatly reduced; great implementation values are realized.
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Paragraph 0036; 0037; 0040; 0043; 0046
(2018/09/21)
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