42% |
In butan-1-ol; for 12h;Inert atmosphere; Reflux; |
A reaction mixture consisting of 2,3-diaminonaphthalene (0.75g, 4.74mmol), 3,4-dihydro-2H-pyran-5-carbaldehyde (0.53g, 4.74mmol) and n-butanol (15mL) was refluxed under argon for 12h. A red, fairly insoluble precipitate was filtered off and washed thoroughly with ethanol and diethyl ether. Red microcrystals, yield 0.25g (42%), mp 312-316C (decomposition). Analytical sample was recrystallized from DMF. Crystals suitable for X-ray measurements were grown from DMF. 1H NMR (300MHz, DMSO-d6, delta ppm): 1.76 (m, 4H, CH2CH2O), 2.46 (m, 4H, CH2), 3.54 (m, 4H, CH2O), 4.51 (t, J=5.0Hz, 2H, OH), 7.31 (m, 4H, Ar-H), 7.72 (m, 4H, Ar-H), 7.85 (s, 4H, H1,6,12,17), 8.26 (d, J=6.0Hz, 4H,=CHN), 12.72 (t, J=6.0Hz, 2H, NH); 13C NMR (75MHz, DMSO-d6, delta ppm): 28.78 (CH2CH2O), 35.34 (CH2), 59.87 (CH2O), 108.86, 109.88, 124.82, 126.89, 131.05, 136.91 (Caromat.N), 148.47 (=CHN); IR (ATR) numax(cm-1): {3372, 3311} (OH), {3194, 3176} (NH), 3053 (Ar-H), {2941, 2928, 2872} (CH2), {1640, 1620, 1596, 1547} (C=N, Ar), 1297, 1272 (C-O); ESI-MS: (m/z) 505.4 (M+H+); Anal. Calcd for C32H32N4O2: C, 76.16; H, 6.39; N, 11.10. Found: C, 75.80; H, 6.45; N, 11.15%. |