Title of article :
Expedient synthesis of pyrazoles substituted with amino, hydroxyl and thioamide groups
Author/Authors :
Trofimov، نويسنده , , Boris A. and Mal’kina، نويسنده , , Anastasiya G. and Borisova، نويسنده , , Angela P. and Nosyreva، نويسنده , , Valentina V. and Shemyakina، نويسنده , , Olesya A. and Kazheva، نويسنده , , Olga N. and Shilov، نويسنده , , Gennadii V. and Dyachenko، نويسنده , , Oleg A.، نويسنده ,
Issue Information :
هفته نامه با شماره پیاپی سال 2008
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 :
? , ?-Acetylenic ?-hydroxy nitriles , thiosemicarbazide , pyrazoles , Nucleophilic addition/cyclization , X-ray crystal structure
Journal title :
Tetrahedron Letters
Journal title :
Tetrahedron Letters
