- Increasing the Purity of Lafutidine Using a suicide Substrate
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When preparing lafutidine, we found that the main impurity was dihydrolafutidine. On the basis of the chemical structure of dihydrolafutidine and the mechanism of its production, we decided to use a suicide substrate in the drug preparation to increase the purity of lafutidine. By calculating the energy barrier of the reduction reaction with a quantum-chemical method and evaluating the appropriate physicochemical properties of the terminal olefins, we chose 1-hexene as the suicide substrate to effectively control the formation of dihydrolafutidine in the synthesis of lafutidine. The experimental results showed that the content of the impurity, dihydrolafutidine, decreased from 1.5% to less than 0.05%, proving that using a suicide substrate is an effective method to reduce the formation of the relevant byproduct in drug production. In addition, this method is operationally simple and is suitable for industrial applications.
- Wu, Chengjun,Li, Zhen,Wang, Chunchao,Zhou, Yanan,Sun, Tiemin
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- A novel histamine 2(H2) receptor antagonist with gastroprotective activity. II. Synthesis and pharmacological evaluation of 2-furfuryl-thio and 2-furfurylsulfinyl acetamide derivatives with heteroaromatic rings
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We recently found that N-[3-[3- (piperidinomethyl)phenoxy]propyl]acetamide derivatives with a thioether function showed gastric anti-secretory and gastroprotective activities and that the thioether function (particularly furfurylthio or furfurylsulfinyl) was essential for gastroprotection. In the present study, a series of 2- furfurylthio and 2-furfurylsulfinyl acetamide derivatives were synthesized and evaluated for histamine H2 receptor antagonistic activity, gastric anti- secretory activity and gastroprotective action. Based on the structure of N- [3-[3-(piperidinomethyl)phenoxy]propyl]acetamide, we designed compounds, in which the 3-(piperidinomethyl)phenoxy part is substituted with many types of heteroaromatic ring attached to the tertiary amine and the propyl group is replaced with other carbon linkages. Structure-activity relationships are discussed. 2-Furfurylsulfinyl-N-[4-[4-(piperidinomethyl)-2-pyridyloxy]-(Z)- 2-butenyl]acetamide was the most potent among the tested compounds and was given the code designation FRG-8813.
- Hirakawa, Nobuhiko,Matsumoto, Hajime,Hosoda, Akihiko,Sekine, Akihiro,Yamaura, Tetsuaki,Sekine, Yasuo
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- Method for manufacturing lafutidine crystal with high purity
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The present invention relates to a method for manufacturing a lafutidine crystal form with high purity. The method for manufacturing a novel lafutidine crystal form of the present invention produces a desired crystal form according to temperature control after dissolution, thereby being able to be easily applied to production (scale-up) and stably manufacture the lafutidine crystal form with high purity.
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Paragraph 0084; 0094-0104; 0118-0126
(2020/09/30)
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- Preparation method and application of lafutidine and intermediate thereof
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The invention relates to a preparation method and application of lafutidine and an intermediate thereof. The preparation method of the lafutidine intermediate comprises the following steps: the formula is as shown in the specification, wherein a compound shown as a formula (I) reacts in the presence of an alcohol amine type organic base and at least one type of other alkaline compound, so as to obtain the lafutidine intermediate shown as a formula (II). The preparation method of the lafutidine intermediate, disclosed by the invention, is safe and environmentally friendly, and avoids hidden dangers of safety production, caused by the fact that hydrazine hydrate, methylamine, ethanediamine, hydroxylamine hydrochloride and the like are used; the obtained lafutidine intermediate can be directly subjected to a condensation reaction to obtain the lafutidine, without the need of being further purified; the product is stable in quality and high in purity and does not contain a dihydrolafutidine impurity and the content of total impurities is lower than 0.15%; and the complicated purification is avoided and the whole process is high in yield and low in cost.
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Paragraph 0107-0108; 0111-0115; 0118-0122; 0125-0129; 0132
(2020/01/12)
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- Lafutidine hydroxylamine hydrochloride method of preparation
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The invention relates to a novel chemical synthetic method for lafutidine, and in particular relates to a method for preparing the lafutidine from hydroxylamine hydrochloride serving as aminolysis reagent. The method comprises the following steps of: (1) reacting a compound in a formula 4 with the hydroxylamine hydrochloride and sodium hydroxide so as to obtain a compound in a formula 2; (2) carrying out condensation on the compound in the formula 2 and a compound in a formula 3 so as to obtain the lafutidine in a formula 1. The whole preparation process is as shown in the specification. When in preparation of the key intermediate the compound in the formula 2, the hydroxylamine hydrochloride is chosen for substituting other reagents for aminolysis reaction, and the prepared lafutidine product has higher purity and can reach 99.88%; compared with the condition that the aminolysis reagent is removed from the intermediate, the hydroxylamine is easier to remove; and furthermore, the hydroxylamine hydrochloride is a solid reagent, has high purity and high stability, and industrial production is more easily realized.
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Paragraph 0043-0044
(2016/10/08)
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