Pyridazine-3,6-diones pyridazines, hexahydro

H NMR has been used to study the thermodynamics of the conformational inversion of various pyridazino[l,2-a]pyridazines. In the case of l,2,3,4,6,9-hexahydro-7,8-dimethyl-pyridazino[ 1,2-a ]pyridazine-1,4-dione, analysis of the signals from the C-3 and C-6 methylene protons at -60 °C shows that the energy barrier to the conformational inversion must be less than 43.5 kJ mol-1 (66T3477). 

Ci,H6N202, Hexahydro-3,6-pyridazine-dione, 41B, 270 Ci,H6N2S, 2H-Pyridaz-3-thione, 31B, 117 C4H8N2O, Perhydropyrimidin-2-one, 46B, 1153 CftH8N202f 2,6-Bishydroxyiminopiperazine, 46B, 221 Ci,HioN2f Piperazine (gas-ed), 28, 666 37B, 687... 

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