Structure of a dihydroquinaldine dimer from electrolytic reduction

✍ Scribed by I.W. Elliott; E.S. McCaskill; M.S. Robertson; C.H. Kirksey

• Publisher: Elsevier Science
• Year: 1962
• Tongue: French
• Weight: 174 KB
• Volume: 3
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)70869-0

✦ Synopsis

REWCTICN of quinaldine in acid solution either by zinc metal or at a mercury cathode results in the formation of a dimer of dihydroquinaldine (C20K22N21, m.p. 181-182').1 Electrolytic reduction of quinaldine in alcoholic potassium hydroxide was reported by Levchenko give an isomeric dimer, m.p. 119-120°.2 We originally attempted to prepare Levchenko's dimer in order to investigate its structure, but under the conditions for electrolysis that we employed we obtained none of the dimer of m.p. 119', but one of the products isolated consistently was a compound of m.p. 138-140' that is assigned structure I. The formation of the dimer (I, m.p. 138-140') occurs with the uptake of one mole of hydrogen per mole of dimer [Founds C, 83.01; H, 6.80; N, 9.70; M. W. (Rast) 330. C20H20N2 requires: C, 83.29; H, 6.99; N, 9.71; M. W. 288].3 The dimer is unsaturated and absorbs one mole of hydrogen catalytically to afford a more stable tetrahydroquinaldine diner [II, m.p.