反应详情

The (4-amino-2-methyl-1H-indol-1-yl)-acetic acid, ethyl ester prepared above (8.59 g) was dissolved in ethyl acetate (175 ml) then triethylamine (5.2 ml, 37 mmol) added followed by acetyl chloride (2.6 ml, 37 mmol). An exotherm to 35° C. was observed and a thick suspension resulted. After stirring for 4 hours during which the mixture was allowed to cool back to ambient temperature, water (85 ml) was added and the ethyl acetate removed by evaporation under vacuum. The solid was collected by filtration, washed with water (25 ml) followed by 50% v/v aqueous acetonitrile (50 ml) then dried in a vacuum oven at 50° C. overnight to provide (4-acetylamino-2-methyl-1H-indol-1-yl)-acetic acid, ethyl ester, as an off-white solid, 7.26 g (77% from (4-nitro-2-methyl-1H-indol-1-yl)-acetic acid, ethyl ester).

1. customto 35° C.
2. customa thick suspension resulted
3. customthe ethyl acetate removed by evaporation under vacuum
4. filtrationThe solid was collected by filtration
5. washwashed with water (25 ml)
6. customthen dried in a vacuum oven at 50° C. overnight