- One-pot synthesis method of praziquantel intermediate
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The invention discloses a one-pot synthesis method of a praziquantel intermediate. The method comprises the steps of adding N-phenylethyl aminoacetaldehyde dialkyl alcohol (A1) and N-cyclohexylformyl glycine (A2) into a reaction vessel, reacting to obtain a compound as shown in a general formula A3, adding a condensation receiving device on the reaction vessel, replacing air in the reaction container and the condensation receiving device with nitrogen, carrying out microwave reaction in a microwave reactor, and after the microwave reaction is finished, adding an organic solvent to crystallize to obtain white solid 4-(cyclohexylcarbonyl)-3, 4-dihydro-1-(2-phenethyl)-2-(1h)-pyrazinone (A4). By adopting the method, the high-purity praziquantel intermediate can be prepared, and the industrial production requirement of the praziquantel intermediate can be met.
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Paragraph 0034-0041
(2021/04/14)
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- A palladium-catalyzed intramolecular Heck/Hydrogenation approach towards the synthesis of praziquantel
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Starting from 3-methoxy N-acylpyrazinium salts, a new approach towards the synthesis of the antischistosomal drug praziquantel (PZQ) has been developed. Utilization of a palladium-catalyzed intramolecular Heck reaction to form dehydro-PZQ followed by a Hydrogenation step, in a stepwise or one-pot manner, allowed for the gram scale synthesis of PZQ in 4 or 5 steps and in good overall yields. This methodology proved to be well suited for generating the pyrazino[1,2-a] isoindole and pyrazino[1,2-a] benzazepine analogues of PZQ.
- Williams, Alfred L.,St. Hilaire, Valentine R.
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p. 6712 - 6717
(2017/10/25)
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- A concise and highly efficient synthesis of praziquantel as an anthelmintic drug
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A concise and practical synthesis of praziquantel as anthelmintic drug is described. The key steps include a monoalkylation of ethanolamine for the preparation of 2-(2-hydroxyethylamino)-N-phenethylacetamide and a mild oxidation protocol with SO3-Py/DMSO as oxidant to transform alcohol into the corresponding aza-acetal. The telescoped synthesis is composed of five steps without purification of the intermediates, providing an overall yield of 80% with 99.8% purity after crystallization.
- Yang, Zhezhou,Zhang, Lin,Jiao, Huirong,Bao, Rusheng,Xu, Weiwei,Zhang, Fuli
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p. 1983 - 1993
(2016/11/26)
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- Synthesis of praziquantel via N-acyliminium ion cyclization of amtoo acetals through several synthetic routes
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Syntheses of praziquantel have been accomplished via an N-acyliminium ion by several routes including the tandem nucleophilic addition-cyclization sequence from amido acetal (8) or (10) and a stepwise cyclization of enamide (9) generated from the nucleophilic addition reaction of amido acetal (8) or (10).
- Kim, Joong Hyup,Lee, Yong Sup,Kim, Choong Sup
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p. 2279 - 2285
(2007/10/03)
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- A NEW SYNTHESIS 2-ACYL-1,2,3,6,7,11b-HEXAHYDROPYRAZINOISOQUINOLIN-4-ONES BASED ON N-CYANOMETHYL DERIVATIVES OF 2-PHENYL-ETHYLAMIDES OF ACYLGLYCINES
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A new route for the synthesis of 2-acyl-1,2,3,6,7,11b-hexahydropyrazinoisoquinolin-4-ones has been studied which includes a stage in which substituted piperazinones are obtained by reductive cyclization of N-cyanomethyl derivatives of 2-phenylethylamides of acylglycines under influence of Raney alloy in formic acid.
- Shekhter, O. V.,Kuklenkova, O. B.,Sergovskaya, N. L.,Tsizin, Yu. S.
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p. 170 - 173
(2007/10/02)
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