5625-67-2Relevant articles and documents
Preparation method of sitagliptin intermediate
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Paragraph 0024; 0028-0029; 0053-0054, (2021/02/13)
The invention relates to a preparation method of a sitagliptin intermediate, and belongs to the technical field of drug intermediate synthesis. In order to solve the problems of low product yield andpoor environmental protection property in the prior art, the invention provides a preparation method of a sitagliptin intermediate, and the method comprises the following steps: reacting 2-piperazinone with hydrazine hydrate in an alcohol solvent to generate piperazine hydrazone; in an acetonitrile or ether solvent, reacting the piperazine hydrazone with ethyl trifluoroacetate to obtain a corresponding intermediate N -[(2Z-) piperazine -2-subunit] trifluoroacethydrazide; and performing cyclization and salification reaction on the N -[(2Z-) piperazine -2-subunit] trifluoroacethydrazide in an alcohol solvent under the action of hydrochloric acid to obtain the corresponding sitagliptin intermediate 3-trifluoromethyl 5, 6, 7, 8-tetrahydro-1, 2, 4-triazole [4, 3-a] pyrazine hydrochloride. The reaction has the effects of high selectivity and high product yield.
NH insertion reactions catalyzed by reusable water-soluble ruthenium(II)-hm-phenyloxazoline complex
Abu-Elfotoh, Abdel-Moneim
supporting information, p. 4750 - 4754 (2017/11/29)
A water-soluble Ru(II)-hm-pheox complex was efficiently catalyzed NH insertion of EDA with a broad class of amine derivatives in water/ether biphasic medium to deliver the biologically active precursors α-aminoester products with excellent yields (up to >99%). The products were separated by decantation and the catalyst was washed and reused several times (at least 8 times) without any specific loss of its catalytic activity. The plausible mechanism of the reaction was explained. Additionally, In case of ethylene diamine, the NH insertion product could be transformed to biological active piperazinone compound in high yield. The asymmetric version of this catalytic reaction is under investigation.
Enantioselective synthesis of α-secondary and α-tertiary piperazin-2- Ones and piperazines by catalytic asymmetric allylic alkylation
Korch, Katerina M.,Eidamshaus, Christian,Behenna, Douglas C.,Stoltz, Brian M.,Nam, Sangkil,Horne, David
supporting information, p. 179 - 183 (2015/02/05)
The asymmetric palladium-catalyzed decarboxylative allylic alkylation of differentially N-protected piperazin-2- ones allows the synthesis of a variety of highly enantioenriched tertiary piperazine-2-ones. Deprotection and reduction affords the corresponding tertiary piperazines, which can be employed for the synthesis of medicinally important analogues. The introduction of these chiral tertiary piperazines resulted in imatinib analogues which exhibited comparable antiproliferative activity to that of their corresponding imatinib counterparts.