Crystal Structure Analysis of 4-Oxo, 4-hydroxy- and 4-alkyl-7-bromopyrazolo[5,1-c][1,2,4]triazines

The crystal structures of 8-R¹-7-bromo-3-tert-butyl-1-R²-pyrazolo[5,1-c][1,2,4]triazin-4(1H)-ones 1a-c, 2a,c (R¹ = CN, CO₂Et, NO₂, R² = H, 1:1 and 3:1 solvates with DMSO; R¹ = CN, CO₂Et, R² = CH₂Boc), 8-R¹-7-bromo-3-tert-butyl-1-R²-1,4-dihydropyrazolo[5,1-c][1,2,4]triazin-4-ols 3a,b (R¹ = CN, R² = n-Bu; R¹ = Br, R² = CH₂Boc), 1,4-dihydro- and aromatic 7-R³-3-tert-butyl-4-R⁴-8-methylpyrazolo[5,1-c][1,2,4]triazines 5a,b, 6 (R³ = H, R⁴ = n-Pr; R³ = Br, R⁴ = n-Bu) were investigated by X-ray diffraction analysis. The structural preferences and different packing modes based on the intermolecular interactions were analyzed by the Hirshfeld surface and energy framework analysis.

The crystal structures of ten 3-tert-butyl-4-oxo, 4-hydroxy- and 4-alkyl-7-bromopyrazolo[5,1-c][1,2,4]triazines including non-solvated, 1:1 and 3:1 solvates with DMSO were investigated by single crystal X-ray diffraction, Hirshfeld surface and energy framework analyses.

The online version contains supplementary material available at 10.1007/s10870-022-00973-x.