反应详情

Under stirring, 4.6 parts of anhydrous aluminum chloride are added to 100 volume parts of dry tetrahydrofuran, followed by the addition of 3.11 parts of trans-3-(4-oxo-4H-1-benzopyran-3-yl)-acrylonitrile and 4.5 parts of sodium azide. The whole mixture is refluxed for 28 hours and, then, 35 volume parts of 15 weight% hydrochloric acid are added to the resulting mixture, followed by distilling off tetrahydrofuran under reduced pressure. The resulting residue is recovered by filtration and recrystallized from methanol, dimethylformamide-water and, then, from methanol. This procedure yields trans-1-(4-oxo-4H-1-benzopyran-3-yl)-2-(1H-tetrazol-5-yl) ethylene as light-yellow needles. Melting point: 254.5°-255° C.(decomp. with foaming).

1. temperatureThe whole mixture is refluxed for 28 hours
2. distillationby distilling off tetrahydrofuran under reduced pressure
3. filtrationThe resulting residue is recovered by filtration
4. customrecrystallized from methanol, dimethylformamide-water