反应详情

4.4 g (20 mmol) 6-Nitro-1H-indole-2-carboxylic acid methyl ester (190) was dissolved in 80 mL methanol and was treated with 30 mL 1M NaOH overnight at 55 C°. The methanol was evaporated, the remaining aqueous solution was diluted to 100 mL and was acidified to pH 2 using concentrated HCl. The precipitate was filtered off, washed three times with water then dried to give 3.92 g (95%) 191 as yellow powder. The NMR was consistent with the structure. 191 was used without further purification.

1. customThe methanol was evaporated
2. additionthe remaining aqueous solution was diluted to 100 mL
3. filtrationThe precipitate was filtered off
4. washwashed three times with water
5. customthen dried