- Preparation method of cilnidipine
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The invention relates to a preparation method of cilnidipine. The invention provides a preparation method of cinnamyl 3-aminobut-2-enoate, which comprises the following step: carrying out amination reaction on cinnamyl acetoacetate and ammonium carbonate to obtain the cinnamyl 3-aminobut-2-enoate. On the basis, the invention further provides a method for preparing cilnidipine by taking the cinnamyl 3-aminobut-2-enoate as a raw material. The method provided by the invention is relatively low in reaction temperature, relatively short in reaction time, relatively high in product yield and purity,and simple in aftertreatment.
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Paragraph 0026; 0051-0056; 0063-0074; 0076
(2021/02/20)
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- Preparation method of cilnidipine
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The invention discloses a preparation method of high-purity cilnidipine. Methoxyethyl acetoacetate reacts with m-nitrobenzaldehyde to generate 2-(3-nitrobenzylidene) methoxyethyl acetoacetate, and the2-(3-nitrobenzylidene) methoxyethyl acetoacetate reacts with cinnamyl 3-aminocrotonate to generate cilnidipine. According to the method, the refining step of the 2-(3-nitrobenzylidene) methoxyethyl acetoacetate is added; the problem that impurities in the cilnidipine bulk drug are difficult to remove is solved, the subsequent refining process of the cilnidipine is simpler, and the purity of the finished product is high. The method has the advantages of simple synthesis process, complete reaction, high yield and low cost, and is very suitable for industrial production. .
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Paragraph 0029-0045
(2020/05/08)
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- Cilnidipine preparation method
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The invention provides a cilnidipine preparation method. The method includes the steps that 2-(3-nitrophenyl methylidene) methoxyethyl acetoacetate and 3-amino-2-butenoic acid cinnamyl ester serve as reaction raw materials and react under catalysis of concentrated hydrochloric acid to obtain cilnidipine. A common inorganic catalyst is adopted in the method for catalysis reaction so that reaction time can be effectively shortened; besides, quality of a crude product is high, the yield is high, and cilnidipine has metallic luster. The requirement for refining of reaction is low. Purity of the crude product is good, and the quality requirement can be basically met through one time of refining. The technology is reasonable in design, purity of the refined cilnidipine product is high, and the quantity of any impurity and total impurities is small.
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Paragraph 0084-0100
(2016/10/07)
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- Antihypertensive 1,4-dihydropyridines having a conjugated ester
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1,4-dihydropyridine derivatives represented by the following general formula, STR1 in which R3 is a combination of an unsaturated straight chain hydrocarbon group or derivative thereof connected by a single bond with an unsaturated hydrocarbon group or derivative thereof so that the unsaturated carbon atoms of the two groups are in conjugated relationship. These compounds have a hypotensive action the effective time of which is long, which makes the blood pressure descend slowly, and the toxicity of which is low.
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