Preparation method for cyan coupler intermediate

Abstract

The invention discloses a preparation method for a cyan coupler intermediate. The preparation method comprises the following steps: with 4-t-butyl-benzoylhydrazine and ethyl 3-ethoxy-3-iminopropionate as raw materials, reacting 4-t-butyl-benzoylhydrazine with ethyl 3-ethoxy-3-iminopropionate in a lower-ester solvent at 50 to 100 DEG C, carrying out cooling to room temperature after completion of the reaction and then carrying out filtering so as to obtain ethyl 3-[2-(4-t-butyl-phenyl)-hydrazyl]-3-iminopropionate used as a transition intermediate; and subjecting ethyl 3-[2-(4-t-butyl-phenyl)-hydrazyl]-3-iminopropionate to reaction in an alkaline aqueous solution at 70 to 90 DEG C, carrying out cooling to room temperature after completion of the reaction, and successively carrying out neutralization via halogenated acid, filtering and drying so as to obtain the cyan coupler intermediate 2-[3-(4-t-butyl-phenyl)-1H-1,2,4-triazolyl-5]-propionic acid.

Description

technical field [0001] The invention relates to a preparation method of 2-[3-(4-tert-butylphenyl)-1H-1,2,4-triazole-5]-propionic acid, an intermediate of a pyrrolotriazole cyan coupler. Background technique [0002] Pyrrolotriazolidine coupler is a silver halide photosensitive material for color photography. It has excellent coupling activity, thermal stability, light and heat fastness and chromaticity of dye images. It has extremely high value and huge market prospect , 2-[3-(4-tert-butylphenyl)-1H-1,2,4-triazole-5]-propionic acid is the raw material for the synthesis of pyrrolotriazole blue coupler, thus synthesizing intermediate 2 -[3-(4-tert-butylphenyl)-1H-1,2,4-triazole-5]-propionic acid has great practical significance. [0003] So far, the synthetic methods of 2-[3-(4-tert-butylphenyl)-1H-1,2,4-triazole-5]-propionic acid reported in the literature are as follows: [0004] 1), microwave radiation method [0005] [0006] K.S.Yeung et al. (Tetrahedron Letters 46(...

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Problems solved by technology

[0013] Scott S.Woodard and Kevin D.Jerome et al mentioned in the literature (Combinatorial Chemistry & High Throughput Screening, 2011, 14, 132-137) that acetonitrile solvents were used to heat hydrazide-based compounds and imide compounds at 50°C and 105°C, respectively. The corresponding product is obtained by the reaction, and the use of acetonitrile solvent is not good for production safety, and it is troublesome to deal with

In the later stage of the reaction, potassium carbonate needs to be introduced and heated again, the reaction is cumbersome and the product yield is low

[0014] The three main disadvantages of the above-mentioned method are that the reaction condition requirements are high, the highly toxic solvent acetonitrile, and the yield are low.

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