反应详情

To a mixture of 80% hydrazine hydrate (1.64 g, 26.2 mmol) and methanol (5.0 ml) was dropwise added a solution of 4-(pyridin-2-yl)benzaldehyde (1.5 g, 8.2 mmol) in methanol (5.0 ml) at 25° C. over 10 minutes. After the dropwise addition, the mixture was stirred for 30 minutes. Methanol and excess hydrazine hydrate were evaporated under reduced pressure. The residue was crystallized and 4-(pyridin-2-yl)benzaldehyde hydrazone was obtained as crude crystals at a yield of 1.6 g (yield: 100%). The percentage of the area of 4-(pyridin-2-yl)benzaldehyde hydrazone in the crude crystals as determined by liquid chromatography was 94.3%. crude crystals melting point: 65.7-67.8° C. IR(KBr)cm−1: 3700-3000, 1636, 1590, 1468, 1432, 1394, 1150, 1114, 924, 840, 778, 742, 726. 1H-NMR(CDCl3) δ: 5.60(s,2H), 7.22(m,1H), 7.65(d,2H), 7.74(m,2H), 7.78(s,1H), 8.00(d,2H), 8.69(d,1H)

1. additionAfter the dropwise addition
2. customMethanol and excess hydrazine hydrate were evaporated under reduced pressure
3. customThe residue was crystallized