Expedient synthesis of pyrazoles substituted with amino, hydroxyl and thioamide groups |
| |
| Authors: | Boris A. Trofimov,Anastasiya G. Mal&rsquo kina,Valentina V. Nosyreva,Olga N. Kazheva,Oleg A. Dyachenko |
| |
| Affiliation: | a A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, 1 Favorsky Str., 664033 Irkutsk, Russia
b Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1 Academician Semenov Str., 142432 Chernogolovka, Russia |
| |
| Abstract: | The reaction of α,β-acetylenic γ-hydroxy nitriles with thiosemicarbazide, under mild conditions (rt, no catalyst, in 1:1 aqueous ethanol, 4-14 h), proceeds chemo-, regio- and stereoselectively to give atypically so far inaccessible tri-functionalized (amino, hydroxyl and thioamide groups) pyrazoles in 53-91% yields. The hydroxyl function is easily protected by using the corresponding acetals of the starting acetylenic hydroxy nitriles. |
| |
| Keywords: | α,β-Acetylenic γ-hydroxy nitriles Thiosemicarbazide Pyrazoles Nucleophilic addition/cyclization X-ray crystal structure |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
