反应详情

Indole-2-carboxylic acid (1.29 g, 8.0 mmol) was suspended in 20 ml dry toluene and diphenyl-phosphoryl azide (2.64 g, 9.6 mmol) added. Triethylamine (0.816 g, 8.0 mmol) was then added drop-wise and the mixture stirred at room temperature for 0.5 hour. The solution was heated to 80° C. and the suspension cleared immediately. Then 2-Amino-4-chloro-5-methyl-benzenesulfonic acid (1.661 g, 8.0 mmol) was added and triethylamine (0.816 g, 8.0 mmol. The mixture was stirred for 3 hours at 80° C. and then the reaction mixture was diluted with 200 ml ethyl acetate and washed with saturated aqueous sodium bicarbonate. The organic phase was then extracted 3 times with distilled water. The title compound was precipitated from the aqueous phase with addition of HCl, filtered and recrystallised from ethyl acetate/heptane to yield 1.6 g (53%) of title compound as light purple crystalline solid (m.p. 284-286° C.; decomposition).

1. temperatureThe solution was heated to 80° C.
2. stirringThe mixture was stirred for 3 hours at 80° C.
3. washwashed with saturated aqueous sodium bicarbonate
4. extractionThe organic phase was then extracted 3 times with distilled water
5. customThe title compound was precipitated from the aqueous phase with addition of HCl
6. filtrationfiltered
7. customrecrystallised from ethyl acetate/heptane