Methylamine Acetate → 4-(5-Chloroindol-3-yl)-2-methylamino-4-oxo-2-butenoic acid ethyl ester

Participants

Reaction Steps

To a solution of 0.59 g (2.0 mmol) of 4-(5-chloroindol-3-yl)-2-hydroxy-4-oxo-2-butenoic acid ethyl ester prepared in Example 1(1) in 95% EtOH (10 ml) was added 0.55 g (6.0 mmol) of methylamine acetate. After refluxing for 2.5 hours, the reaction mixture was concentrated and the residue was dissolved in ethyl acetate. The ethyl acetate was washed with water, dried, and then concentrated. The resulting residue was chromatographed on silica gel (ethyl acetate as eluant) to give 0.23 g of the titled compound as oil. Yield: 38%.

Provenance & Evidence