2-Imino-6,7,8-trihydroacenaphthylen-1-amine: synthesis and reduction with sodium

The hydrolysis of the tetrasodium salt of dpp-bian (dpp-bian is 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) affords the organic compound 1,6,7,8-H4-dpp-bian (1). This reaction is accompanied by the protonation of the nitrogen atom of the diimine moiety and one ring of the naphthalene system of the molecule. The reduction of 1 with one equivalent or an excess of sodium metal in 1,2-dimethoxyethane gives the salts [(6,7,8-H3-dpp-bian)Na(dme)2] (2a) and [(5,6,7,8-H4-dpp-bian)Na2(dme)2] (3), respectively. The exchange reaction of compound 1 with one equivalent of sodium amide in diethyl ether affords the monosodium salt [(6,7,8-H3-dpp-bian)Na(Et2O)2] (2b). Compounds 1–3 were characterized by NMR and IR spectroscopy and elemental analysis. The molecular structures of 1–3 were determined by X-ray diffraction.