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One-pot method for preparing indoline-based methine dyes

A technology of indoline-based dyes, which is applied in the field of preparation of indoline-based methine dyes, can solve the problems of energy consumption and associated distillation residues, difficult procurement of raw materials VI, and rising production costs, achieving smooth undertaking and operability And the effect of stability and high conversion rate of the main reaction

Active Publication Date: 2020-06-26
宁波龙欣精细化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0014] Compared with the third process, the second process also presents a certain degree of disadvantage: the raw material Ⅵ is not easy to purchase, and often needs to be self-produced, which adds a production process and a stream of waste water
The defect of the third process is that it is greatly affected by the price of trimethyl orthoformate. For example, in the first half of 2018, the price of trimethyl orthoformate suddenly rose by more than 250%, resulting in a sharp increase in production costs, which is significantly higher than that of the second process.
[0023] Although several routes are involved in the above-mentioned synthetic literature related to Ⅲ, the yield is not good, the highest is no more than 70%, and more than one stream of waste water is produced, and accompanied by a vacuum distillation process, which consumes considerable energy and associated distillation residue

Method used

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  • One-pot method for preparing indoline-based methine dyes
  • One-pot method for preparing indoline-based methine dyes
  • One-pot method for preparing indoline-based methine dyes

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0062] Embodiment 1 (dye Ⅰ-1)

[0063] In a 250mL flask, add 150mL of methanol, 28.3g of 4-carboxyphenylhydrazine hydrochloride (0.15mol), 18g of sulfuric acid (0.18mol), 13.3g of methyl isopropyl ketone (0.155mol), and raise the temperature to slightly reflux for 10~ 12h to the end of the reaction. Add an appropriate amount of sodium bicarbonate to neutralize, filter, wash the filter cake with an appropriate amount of methanol, and merge the methanol cleaning liquid into the mother filtrate.

[0064] Add 17g of sodium bicarbonate to the above-mentioned condensation filtrate, raise the temperature to slight reflux, slowly add 26.5g of dimethyl sulfate (0.21mol) dropwise, after the drop is complete, keep it under reflux for 1-1.5h to the end of the reaction, filter to obtain the methylated solution .

[0065] Weigh 26.8g of 1-phenyl-3-methyl-4-formyl-5-pyrazolone (0.134mol), add to the above methylation solution, add 5g of p-toluenesulfonic acid, heat up to reflux reaction 5 ...

Embodiment 2

[0067] Embodiment 2 (dye Ⅰ-1)

[0068] In a 250mL flask, add 150mL of methanol, 28.3g of 4-carboxyphenylhydrazine hydrochloride (0.15mol), 18g of sulfuric acid (0.18mol), 13.3g of methyl isopropyl ketone (0.155mol), and raise the temperature to slightly reflux for 10~ 12h to the end of the reaction. After cooling, add an appropriate amount of magnesium oxide to neutralize, filter, wash the filter cake with methanol, and merge the methanol cleaning liquid into the mother filtrate.

[0069] Add 4.4g of magnesium oxide to the above-mentioned condensation filtrate, raise the temperature to slight reflux, slowly add 26.5g of dimethyl sulfate (0.21mol) dropwise, after the dropwise completion, reflux for 1-1.5h to the end of the reaction, and filter to obtain the methylated solution.

[0070] Weigh 27g of 1-phenyl-3-methyl-4-formyl-5-pyrazolone (0.135mol), add it to the above methylation solution, add 5g of p-toluenesulfonic acid, heat up to reflux for 5~ 6h later to the end of the...

Embodiment 3

[0071] Embodiment 3 (dye Ⅰ-1)

[0072] Replace "5g p-toluenesulfonic acid" with "5g acetic acid", and the rest are the same as in Example 1 to obtain 57.9g of the target dye of formula I-1 (yield 86.7%, compared with the standard product, ΔC 0.08, ΔE 0.25, intensity 99.7%.).

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Abstract

The invention discloses a method for preparing an indoline polymethin dye via a one-pot method. The method comprises the following steps of: carrying out condensation and ring closing on phenylhydrazine or para-substituted phenylhydrazine hydrochloride and methyl isopropyl ketone in an alcohol solvent under the catalysis of sulfuric acid so as to generate 2,3,3-trimethylindole or a derivative thereof, adding alkali to carry out neutralization, and carrying out filtration to remove salt; adding an appropriate acid-binding agent in the filtrate, dropwise adding dimethyl sulfate to generate 1,3,3-trimethyl-2--methylene indoline or a derivative thereof; and directly adding 1-phenyl-3-methyl-4-formyl-5-pyrazolone, and carrying out acid catalysis and condensation to generate a target dye. The method has the advantages of being easy to operate, high in yield, low in cost and less in wastewater.

Description

technical field [0001] The invention relates to the technical field of chemical dyes, in particular to a preparation method of indoline-based methine dyes. Background technique [0002] At present, solvent dyes with the structure of formula I are mainly used for coloring thermoplastic resins such as PS, PET, ABS, ABS / PC, and PET pre-spinning coloring. [0003] [0004] where: R 1 = H, Cl, OCH 3 or COOCH 3 . [0005] Its preparation process route is mainly divided into three types: [0006] One is 5-substituent-1,3,3-trimethyl-2-methyleneindoline-ω-aldehyde such as general formula IV and 1-phenyl-3-methyl-5 - Derived from condensation of pyrazolone (DE1172387 method for preparing methine dye). [0007] The second is 5-substituting group-1,3,3-trimethyl-2-methylene indoline as general formula III and 1-phenyl-3-substituting group-4-aldehyde group as general formula VI - Obtained by condensation of 5-pyrazolone (DE 1154894 Preparation method of slightly water-soluble ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D403/06C09B23/10
CPCC07D403/06C09B23/102C09B23/105
Inventor 丁秋龙陈君良
Owner 宁波龙欣精细化工有限公司
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