反应详情

温度

20 °C

Alterative A. To a mixture of ethyl 1-methyl-5-nitro-1H-indole-2-carboxylate (420 g), from step (a) or commercial sources, and 10% palladium on carbon catalyst (50% wet) (42 g) in ethanol (4200 mL) was added a solution of ammonium formate (541.5 g) in demineralized water (840 mL) at between 25-35° C. over 3 hours. The mixture was stirred for 18 hours at 20° C., and then filtered, washing the solids with ethanol (2100 mL). The combined filtrate and washings were concentrated to 840 mL under vacuum at about 20° C. The resulting slurry was granulated at 5° C., filtered, washed with chilled ethanol (420 mL), and dried to give product ethyl 5-amino-1-methyl-1H-indole-2-carboxylate (316.5 g, 86%).

1. filtrationfiltered
2. washwashing the solids with ethanol (2100 mL)
3. concentrationThe combined filtrate and washings were concentrated to 840 mL under vacuum at about 20° C
4. customwas granulated at 5° C.
5. filtrationfiltered
6. washwashed with chilled ethanol (420 mL)
7. customdried