METHOD OF PRODUCING 3-SUBSTITUTED (INDOL-1-YL)-ACETIC ACID ESTERS Russian patent published in 2018 - IPC C07D209/18 C07D401/06 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for producing a compound of general formula (I) . In formula (I) R¹ is fluorine, chlorine or bromine; R² represents C₁-C₆ alkyl or benzyl; and R³ represents C_5-14 aryl containing up to three rings, or C_5-14 heteroaryl containing at least one heteroatom selected from N, O and S, and containing up to three rings, optionally substituted with one or more substituents selected from halogen, OH, CN, R⁴, COR⁴, CH₂R⁴, OR⁴, SR⁴, SO₂R⁴ or SO₂YR⁴; R⁴ represents C₁-C₆ alkyl, C₃-C₈ cycloalkyl, C_4-8 a heterocyclyl containing at least one heteroatom selected from N, O, and S and which may be optionally substituted with one or more oxo groups, C_5-14 aryl containing up to three rings, or C_5-14 heteroaryl containing at least one heteroatom selected from N, O and S and containing up to three rings, any of which may be optionally substituted with one or more substituents selected from halogen, OH, CN, NO₂, C₁-C₆ alkyl or O(C₁-C₆ alkyl); and Y is NH or linear or branched C₁-C₄-alkylene chain. Method includes: I) reacting the compound of general formula (II) with the compound of general formula (III) in a suitable solvent and in the presence of titanium tetrachloride, where the ratio of the compound of general formula (II) to the solvent ranges from 1:8 to 1:20 weight/volume, and II) reacting the product of step (I) with a reducing agent to form a compound of general formula (I). Also provided is a method for preparing a compound of formula (V).

EFFECT: method according to the invention is applicable on an industrial scale to many different indole derivatives of acetic acid, can be carried out using a significantly reduced amount of solvent and can increase the yield of the product.

22 cl, 3 tbl, 5 ex