ortho-Ketimines of 1,8-Bis(dimethylamino)naphthalene: Synthesis, Hydrolytic Stability and Transfer of Basicity from Proton Sponge Moiety to the Imino Function

A series of 2-ketimines and 2,7-diketimines of 1,8-bis(dimethylamino)naphthalene (proton sponge, DMAN) have been obtained and converted into the corresponding ketones via acidic hydrolysis. Investigation of structural and spectral properties of DMAN-based imines led to the conclusion that their unusual hydrolytic stability results from a combination of different factors the most important of which is a strong electron-donor effect of peri-dimethylamino groups.