METHOD OF PRODUCING 2-SUBSTITUTED 1-HYDROXY-1H-INDOLE-5,6-DICARBOXYLIC ACIDS Russian patent published in 2017 - IPC C07D209/42 C07D409/04 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing 2-substituted 1-hydroxy-1H-indole-5,6-dicarboxylic acids, where R=C₆H₅ or 4-CH₃C₆H₄, or 4-OCH₃C₆H₄, or 2-thienyl, which can be used as precursors for synthesis of biologically active substances and medicinal preparations. Method of producing 2-substituted 1-hydroxy-1H-indole-5,6-dicarboxylic acids includes two steps. At first step substituted 4-nitro-5-(2-oxoethyl)phthalonitriles are heated in a sulphuric acid solution to form corresponding substituted 4-[2-R-2-oxoethyl]-5-nitrobenzene-1,2-dicarboxylic acids. At second step substituted 4-[2-R-2-oxoethyl]-5-nitrobenzene-1,2-dicarboxylic acids are reduced with tin dichloride to obtain desired 2-substituted 1-hydroxy-1H-indole-5,6-dicarboxylic acids.

EFFECT: use of disclosed method for synthesis of 2-substituted 1-hydroxy-1H-indole-5,6-dicarboxylic acids enables to obtain novel, previously not described in literature indole-5,6-dicarboxylic acid.

1 cl, 4 ex