200575-15-1Relevant articles and documents
Preparation method of sildenafil citrate
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Paragraph 0021; 0022; 0044-0047, (2021/04/07)
The invention discloses a preparation method of sildenafil. The method comprises the following steps: activating an intermediate compound B in an aprotic solvent by using thionyl chloride, reducing with 1-methyl-4-nitro-3-propyl-1H-pyrazole-5-formamide in a zinc powder-ammonium chloride system in the presence of an acid-binding agent to obtain an intermediate compound E, and condensing to obtain an intermediate compound C; and cyclizing the intermediate compound C in an alcohol solvent under an alkaline condition to prepare sildenafil. The preparation method disclosed by the invention is short in reaction time, greatly shortens the production period so as to reduce the production cost, and is simple in operation and suitable for large-scale production.
Organic synthesis in a modular robotic system driven by a chemical programming language
Steiner, Sebastian,Wolf, Jakob,Glatzel, Stefan,Andreou, Anna,Granda, Jaros?aw M.,Keenan, Graham,Hinkley, Trevor,Aragon-Camarasa, Gerardo,Kitson, Philip J.,Angelone, Davide,Cronin, Leroy
, (2018/12/14)
The synthesis of complex organic compounds is largely a manual process that is often incompletely documented. To address these shortcomings, we developed an abstraction that maps commonly reported methodological instructions into discrete steps amenable to automation. These unit operations were implemented in a modular robotic platform by using a chemical programming language that formalizes and controls the assembly of the molecules. We validated the concept by directing the automated system to synthesize three pharmaceutical compounds, diphenhydramine hydrochloride, rufinamide, and sildenafil, without any human intervention. Yields and purities of products and intermediates were comparable to or better than those achieved manually. The syntheses are captured as digital code that can be published, versioned, and transferred flexibly between platforms with no modification, thereby greatly enhancing reproducibility and reliable access to complex molecules.
A method for preparing sildenafil
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Paragraph 0023; 0025, (2017/04/08)
The invention discloses a preparation method of sildenafil and relates to the technical filed of chemical medicine synthesis. The method includes following steps: (1) carrying out a reaction between 2-ethyoxyl-5-(4-methylpiperazine-1-ylsulfonyl)benzoic acid with thionyl chloride in the presence of a catalyst to prepare an intermediate I; (2) carrying out a reaction between the intermediate I with 4-amino-1-methyl-3-propyl-1H-pyrazole-5-methanamide in the presence of an acid-binding agent to prepare an intermediate II; (3) carrying out a cyclization reaction to the intermediate II in the presence of a specific alkali to obtain a crude product of sildenafil; and (4) performing recrystallization to obtain a pure product of sildenafil. In the invention, reduced pressure distillation for removing exceeded thionyl chloride is unnecessary so that pollution is avoided. Meanwhile, the preparation method can reduce device investment, can simplify technology and can increase efficiency.