反应详情

2,4-Dibromo-5-(4H-1,2,4-triazol-3-yl)thiophene-3-carbonitrile (0.80 g, 2.4 mmol) was placed in a 500 mL round bottom flask and tetrahydrofuran (50 mL, 600 mmol) was added. To the resulting solution were added dihydropyran (1.31 mL, 14.4 mmol) and p-toluenesulfonic acid monohydrate (0.683 g, 3.59 mmol). The mixture was stirred for 3 h at rt. The solution was then poured into 20 mL water and extracted with 40 mL ethyl acetate twice. The combined organic layers were evaporated in vacuo. The residue was purified by column chromatography using 0-35% EtOAc in hexane to afford a solid product (0.842 g, yield 84%). LCMS: (AA) ES+, 417, 419, 421. 1H NMR (300 MHz, CDCl3) δ: 8.38 (s, 1H), 5.55-5.60 (m, 1H), 4.06-4.10 (m, 1H), 3.68-3.78 (m, 1H), 2.15-2.28 (m, 1H), 2.01-2.13 (m, 2H), 1.66-1.80 (m, 3H).

1. extractionextracted with 40 mL ethyl acetate twice
2. customThe combined organic layers were evaporated in vacuo
3. customThe residue was purified by column chromatography