反应详情

In general, a beta-ketoester (e.g. ethyl acetoacetate) is treated with an amine (e.g. 2-thiophenemethyl amine) in the presence of an organic acid (e.g. para-toluenesulfonic acid) and 1,4-benzoquinone to produce a 5-hydroxyindole-3-carboxylic acid (e.g. 5-hydroxy-2-methyl-1-(2-thiophenemethyl)indole-3-carboxylic acid) after hydrolysis of the ester with a strong base such as sodium hydroxide in a suitable solvent such as ethanol. The carboxylic acid is further reacted with an amine in the presence of N-(3-dimethylaminopropyl)-N′-ethylcarbodimide (EDC) to produce 5-hydroxyindole-3-carboxamide (e.g. 3,4-difluorophenylmethyl 5-hydroxy-2-methyl-1-(2-thiophenemethyl)indole-3-carboxamide). The carboxylic acid may also be treated with an alcohol or thiol in the presence of EDC to produce an ester and thiol ester derivatives, respectively,