2-Amino-5,7-diethyl-3-phenyl-1,6-naphthyridine → 5,7-diethyl-3-phenyl-1,6-naphthyridin-2(1H)-one

Participants

Reaction Steps

A solution of sodium nitrite (3.2 g) in water (64 ml) was added dropwise over 45 minutes to a solution of compound B (2.0 g) in 2M hydrochloric acid (150 ml). The mixture was stirred for a further 1 hour and then the suspended white solid was collected by filtration and dried under vacuum to give 5,7-diethyl-3-phenyl-1,6-naphthyridin-2(1H)-one (1.0 g); m.p. >260° C.; NMR (d6 -DMSO): 1.32(t, 3H), 1.33(t, 3H), 3.07(q, 2H), 3.47(q, 2H), 7.41(s, 1H), 7.43-7.55(m, 3H), 7.74-7.85(m, 2H), 8.31(s, 1H); mass spectrum (+ve FAB, methanol/NBA): 279 (M+H)+ ; microanalysis, found: C, 76.9; H, 6.6; N, 9.7%; C18H18N2O.0.25H2O requires: C, 76.4; H, 6.5; N, 9.9 %.

Provenance & Evidence