Synthesis of 7-trifluoromethylpyrazolo[1,5-a]pyridinedicarboxylate

Autor:	Chong Pek Yoke, Mark A. Hatcher, Elie Amine Tabet, Vassil I. Elitzin, Roman Davis, Matthew Salmons, Bing Liu
Rok vydání:	2012
Předmět:	chemistry.chemical_classification Trifluoromethyl Nucleophilic addition Trifluoromethylation Organic Chemistry Aromatization Biochemistry Medicinal chemistry Cycloaddition chemistry.chemical_compound chemistry Ylide Drug Discovery Pyridine Pyrazolopyridine Organic chemistry
Zdroj:	Tetrahedron Letters. 53:6786-6788
ISSN:	0040-4039
Popis:	Two syntheses of 7-trifluoromethylpyrazolo[1,5-a]pyridine dicarboxylate have been described. Approach A utilizes a nucleophilic addition of a trifluoromethyl group to N-p-toluenesulfonyliminopyridinium ylide followed by aromatization and subsequent cycloaddition with diethyl acetylenedicarboxylate to give 1b in modest yield. Approach B involves a selective zincation of pyrazolopyridine dicarboxylate at the C7 position with (TMP)2Zn·2LiCl·2MgCl2 followed by iodination and trifluoromethylation to give 1b in good yield. The process in approach B has been successfully demonstrated on scale.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::0697a2a19b36a73e186f07ec52c5d866 https://doi.org/10.1016/j.tetlet.2012.09.136 Zobrazit plný text záznamu Full Text from ScienceDirect