Synthesis of new halo-substituted pyrazolo[5,1-c][1,2,4]triazines

Шестопалов

2018

Reactions of magnesium 3‐tert‐butyl‐8‐R‐4‐oxo‐4H‐pyrazolo[5,1‐c][1,2,4]triazin‐1‐ides (R = CN, CO2Et) with AlkMgBr led to nucleophilic additions to either side chain or triazine core, with selectivity being dependent on the nature of substituents, as well as on the solvents used. Previously inaccessible C8‐functionalized and C4‐functionalized pyrazolo[5,1‐c][1,2,4]triazines and 3‐tert‐butyl‐3‐ethyl‐4‐oxo‐1,2,3,4‐tetrahydropyrazolo[5,1‐c][1,2,4]triazine were synthesized, and their reactivity and spectral data discussed.

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Interaction of 4‐Oxo‐4H‐pyrazolo[5,1‐c][1,2,4]triazin‐1‐ides with Grignard Reagents

Шестопалов

2018

“…Previously, we investigated diazotization of various 7‐aminopyrazolo[5,1‐ c ][1,2,4]triazines and studied the reactivity of 8‐ R ‐pyrazolo[5,1‐ c ][1,2,4]triazine‐7‐diazonium tetrafluoroborates . Starting from 7‐azido‐3‐ tert ‐butyl‐4‐oxo‐4,6‐dihydropyrazolo[5,1‐ c ][1,2,4]triazine‐8‐carbonylazide, we have synthesized novel pyrazino[2′,3′:3,4]pyrazolo[5,1‐ c ][1,2,4]triazin‐4(6 H )‐ones .…”

Section: Introductionmentioning

confidence: 99%

Synthesis of a New Imidazo[4′,5′:3,4]pyrazolo[5,1‐c][1,2,4]triazine‐4,8‐dione Heterocyclic System

Mironovich

Solyev

et al. 2017

Interaction of Fused 1,2,4‐Triazinone with Diborane/Oxidation: A New Route for the Synthesis of Partially Saturated and Aromatic Pyrazolo[5,1‐c][1,2,4]triazines

Шестопалов

2018

Reactions of 8‐carboxyethyl‐4‐oxo‐3‐tert‐butyl‐4,6‐dihydropyrazolo[5,1‐c][1,2,4]triazine and 8‐butyryl‐4‐oxo‐3‐tert‐butyl‐4,6‐dihydropyrazolo[5,1‐c][1,2,4]triazine with B2H6 in Et2O at 0°C led rapidly to the selective formation of 8‐alkyl‐substituted derivatives. Addition of boron trifluoride led to reduction of the triazine ring, with formation of 1,2,3,4‐tetrahydropyrazolo[5,1‐c][1,2,4]triazines. The latter were spontaneously oxidized by atmospheric oxygen, with formation of 1,4‐dihydro derivatives, or could be converted to the corresponding aromatic pyrazolo[5,1‐c][1,2,4]triazines using oxidative nitration/elimination sequence. These transformations represent a new route for the synthesis of previously inaccessible partially saturated and aromatic pyrazolo[5,1‐c][1,2,4]triazines.