- Chemical synthesis method of Pimobendan
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The invention discloses a chemical synthesis method of Pimobendan. The method comprises steps as follows: acetanilide and 2-methyl-3-(chloroformyl)propionate react to produce 3-p-acetylaminobenzoyl methyl butyrate in a mixed organic solvent under the action of a composite catalyst, 3-p-acetylaminobenzoyl methyl butyrate reacts with a nitration reagent, 3-(4-acetamido-3-nitrobenzoyl)-methyl butyrate is produced and subjected to a reflux reaction with alkali in an alcohol solvent to produce 3-(4-amino-3-nitrobenzoyl) butyrate, 3-(4-amino-3-nitrobenzoyl) butyrate and hydrazine hydrate are subjected to a reflux reaction, 4,5-dihydro-5-methyl-6-(4-amino-3-nitrophenyl)-3(2H)-pyridazinone is produced and reduced with zinc powder in absolute methanol, 4,5-dihydro-5-methyl-6-(3,4-diaminophenyl)-3(2H)-pyridazinone is produced and subjected to a reflux reaction with p-anisaldehyde, and Pimobendan is obtained. The method comprises a few reaction steps, operation is safe and convenient, and the cost is low.
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Paragraph 0020; 0026; 0032; 0038; 0044
(2017/05/23)
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- Studies on agents with vasodilator and β-blocking activities. V. Synthesis and pharmacological activity of the optical isomers of TZC-5665
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Synthesis of the four optical isomers of TZC-5665 (1), a candidate for the treatment of congestive heart failure, was achieved by the reaction of chiral diaminopyridazinone (2) with chiral glycidyl ether (3). The hypotensive and β-blocking activities of 1 and its optical isomers were examined when given intravenously into anesthetized rats. Furthermore these compounds were evaluated for inhibitory activity on cAMP phosphodiesterase III. Among the four optical isomers, R(A),S(B)-one (1c) possessed the essential activities of TZC-5665 (1).
- Seki, Toshimi,Kanada, Arihiro,Nakao, Tomio,Shiraiwa, Masahumi,Asano, Hajime,Miyazawa, Katuhiko,Ishimori, Tsutomu,Minami, Nobuyoshi,Shibata, Kenyu,Yasuda, Kikuo
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- 6-(substituted phenyl)-5-methyl-4,5-dihydropyridazin-3(2H)-ones of medicinal interest. The synthesis of SK&F 94836 and SK&F 95654
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Two synthetic routes to the dihydropyridazinone-cyanoguanidine 4 (SK&F 94836) are described, both proceeding via the anilino compound 6. An efficient synthesis of the dihydropyridazinone-pyridone 5 (SK&F 95654) is reported. This synthesis proceeds via the fluoro-keto-acid 24, with subsequent displacement of the fluoro substituent by 4-pyridone. The surprising effectiveness of water as a solvent in this reaction has been highlighted.
- Burpitt,Crawford,Davies,Mistry,Mitchell,Pancholi,Coates
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p. 1689 - 1695
(2007/10/02)
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