反应详情

温度

25 °C

Thionyl chloride (8 ml, 110 mmol, 5 eq.) was added to a suspension of the compound of formula (III) (4.53 g, 22 mmol, 1 eq.) in dry dioxane (50 ml). The final suspension was refluxed in dry atmosphere (CaCl2 valve) for 2 h, and the reaction turned to a light brown solution while proceeding. The reaction was cooled to 25° C. and organic volatiles were removed under reduced pressure, then dry toluene (25 ml) was added and removed under vacuum, this operation was repeated twice. The brown residue (22 mmol, 1 eq.) was added portion wise to a cooled solution at 0° C. of NaHCO3 (3.7 g, 43.95 mmol, 2 eq.) and 2,2-dimethoxy-ethylamine (2.39 ml, 21.97 mmol, 1 eq.) in dioxane/water 4:1 (100 ml), the suspension was stirred for 2 hours at rt. Organic volatiles were removed under reduced pressure and the yellow precipitate was filtered and dried to give 5-nitro-1H-indole-2-carboxylic acid (2,2-dimethoxy-ethyl)-amide (IV). Yield=5.80 g (90%).

1. customorganic volatiles were removed under reduced pressure
2. additiondry toluene (25 ml) was added
3. customremoved under vacuum
4. customOrganic volatiles were removed under reduced pressure
5. filtrationthe yellow precipitate was filtered
6. customdried