The author of 《The mechanism of thermal eliminations. Part 19. Relative rates of pyrolysis of 2-ethoxypyrazine, 3-ethoxypyridazine, 2- and 4-ethoxypyrimidine, 3-chloro-6-ethoxypyridazine, and 2-chloro-4-ethoxypyrimidine: the effect of the aza ‘substituent’ and π-bond order on the elimination rate》 were Al-Awadi, Nouria; Taylor, Roger. And the article was published in Journal of the Chemical Society in 1986. Formula: C6H8N2O The author mentioned the following in the article:
The kinetics were examined of the 1st-order thermal decomposition of the title compounds into C2H4 and the corresponding aza-substituted pyridines at 650-713 K. The electronic effects of the aza substituent are small; a more important factor appears to be the C-N π-bond order, which accounts for the high reactivity of the pyridazines. The substituent effects of the Cl and aza groups are explicable in terms of the balance between electron withdrawal from the C-O bond, producing activation, and from the N in the cyclic transition state, producing deactivation. The most important reaction step is cleavage of the C-O bond. The statistically corrected rate (per ring N atom) of 2-ethoxypyrimidine is unexpectedly low. This may reflect difficulty in achieving the coplanar transition state in which the lone pairs in the s-orbitals of O and N not involved in the elimination are brought into close proximity. The experimental process involved the reaction of 3-Ethoxypyridazine(cas: 62567-44-6Formula: C6H8N2O)
3-Ethoxypyridazine(cas: 62567-44-6) belongs to pyridazine derivatives.The pyridazine derivatives are mostly present in biologically active compounds and are also present with different pharmacophores. Pyridazines are also important because of their utility in synthetic organic chemistry and in physical organic chemistry.There are reports available for the synthesis of pyridazine and their derivatives by using 2-oxoaldehyes.Formula: C6H8N2O
Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem