| 摘要 |
<p>PURPOSE:To obtain an indole-2-carboxylic acid compound useful as an important intermediate for the synthesis of natural substances and pharmaceuticals on an industrial scale at a low cost by catalytically reducing a 2-nitrophenylpyruvic acid compound in a solvent. CONSTITUTION:This indole-2-carboxylic acid compound of formula II is produced by the catalytic reduction of a 2-nitrophenylpyruvic acid compound of formula I (R is H, Cl, Br, a lower alkyl, a lower alkoxy or amino) in a solvent such as acetic acid or propionic acid preferably in the presence of a palladium catalyst. The solvent to be used in the reaction is a 2-5C carboxylic acid or a 3-6C ketone. Nickel catalyst, platinum catalyst and palladium catalyst can be used as the catalytic reduction catalyst and, among these catalysts, palladium catalyst is most preferable. The palladium catalyst can be produced e.g. by supporting palladium oxide, palladium acetate or palladium metal on a metal oxide or active carbon such as alumina, silica, titania and zirconia.</p> |
