METHOD FOR PRODUCING PIGMENT BASED ON SUBSTITUTED DITHIOLENE NICKEL KITS Russian patent published in 2022 - IPC C07F15/04 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for producing a pigment based on substituted dithiolene nickel complexes for protective elements of multilayer products with asymmetric ligands of the general formula 1. In the formula 1: R₁ is aryl, such as 1- or 2-naphthyl, or phenyl, unsubstituted or containing from 1 to 5 alkoxy groups with normal or branched alkyls C₁-C₁₈, including partially or completely fluorinated ones, in various positions of benzene ring, R₂ is normal or branched alkyl C₁-C₁₈, including partially or completely fluorinated one, cycloalkyl C₅-C₆, allyl, propargyl or unbranched alkyl containing one or more oxygen bridges of (CH₂CH₂O)_nR type in a chain, where n =1-4, and R is methyl, ethyl; aralkyl, where alkyl is a normal alkyl chain C₁-C₄, and aryl is unsubstituted phenyl or containing one or more halogen atoms of fluorine, chlorine or bromine in various positions of benzene ring. The method includes, at the first stage, obtaining a solution of 1-R₂-3-R₁-thiocarbamide, where R₁ and R₂ are the same as described above, wherein R₁ is not equal to R₂, then, at the second stage, oxalyl chloride is added to the reaction mass to form 1-R₂-3-R₁-2-thioxoimidazolidine-4,5-dione, and, at the third stage, metallic nickel and Lavesson reagent are added to the reaction mass cooled to a room temperature to obtain the target product. At the same time, at all three stages of the process, one type of solvent is used, selected from: aromatic, organochlorine, heterocyclic solvent, and all three stages are carried out at the same temperature, namely at the boiling temperature of the selected solvent.

EFFECT: proposed method makes it possible to increase the yield of the target product and speed up the production process compared to other methods for producing such pigments.

1 cl, 3 ex