Synthesis
General procedure for the synthesis of 4,4'-dimethoxy-2,2'-bipyridine nitride from 4,4'-dimethoxy-2,2'-bipyridine nitride: 4,4'-dimethoxy-2,2'-bipyridine 1,1'-dioxide (10) (2.50 g, 10.1 mmol), palladium carbon (5% Pd, 5.16 g, 2.42 mmol, 0.24 eq. ) and ethanol (290 mL) were refluxed for 5 min. An ethanol solution of hydrazine monohydrate (39.3 g, 0.785 mol) was added slowly and dropwise to the mixture (170 mL) over 1 hour. The reaction mixture was continued to reflux for 18 hours and then filtered through Celite. The residue on the diatomaceous earth was washed with hot ethanol. The filtrate and washings were combined, the solvent was removed by evaporation, and the residue was recrystallized from methanol to give the target product 7f (0.412 g, 19% yield). 7f was pale yellow crystals.1H NMR (300 MHz, CDCl3) δ 8.48 (d, J=5.4 Hz, 2H), 7.98 (d, J=2.4 Hz, 2H), 6.86 (dd, J=5.4 Hz, 2.4Hz, 2H), 3.96 (s, 6H).
References
[1] Journal of Organic Chemistry, 2006, vol. 71, # 1, p. 315 - 319
[2] Advanced Synthesis and Catalysis, 2003, vol. 345, # 4, p. 497 - 505
[3] Tetrahedron Letters, 2016, vol. 57, # 49, p. 5489 - 5492
[4] Journal of the American Chemical Society, 1958, vol. 80, p. 2745,2747
