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Preparation method of alpha-naphtholphthalein

A technology of naphtholphthalein and naphthol is applied in the field of preparation of α-naphtholphthalein, can solve the problems of inability to carry out large-scale industrial production, high production cost, low product purity, etc. high rate effect

Inactive Publication Date: 2013-07-10
CHINA LUCKY FILM CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This preparation method has the following disadvantages: (1) the yield of the product is low; (2) the purity of the product is low; (3) the production cost is high, and large-scale industrial production cannot be carried out

Method used

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  • Preparation method of alpha-naphtholphthalein
  • Preparation method of alpha-naphtholphthalein
  • Preparation method of alpha-naphtholphthalein

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] a. Pulverization process: phthalic anhydride and α-naphthol are pulverized into powder in advance;

[0032] b. Reaction process:

[0033] In a 1L three-neck flask equipped with stirring (stirring speed 225rpm), add 190g of phthalic anhydride powder and 350g of α-naphthol powder, the ratio (mol ratio) is 1:1.89, stir evenly and add 150ml of methanesulfonic acid, React at 15°C for 9 hours, and place it at 10-15°C for 62 hours, then raise the temperature to 40°C, keep stirring for 9 hours, and take a sample to measure the color content of the liquid to be 28.85%;

[0034] c. Separation and purification process:

[0035] Dissolve the dark green viscous reactant with 4.6L of absolute ethanol, white insoluble matter precipitates out, filter, at this time the filtrate is strongly acidic, adjust with 437ml of 20% (w / w) NaOH (deionized water configuration) The pH value is neutral (tested with test paper), and a large amount of insoluble matter precipitates out, which is slight...

Embodiment 2

[0037] a. Pulverization process: phthalic anhydride and α-naphthol are pulverized into powder in advance;

[0038] b. Reaction process:

[0039] In a 1L three-neck flask equipped with stirring (stirring speed 225rpm), add 190g of phthalic anhydride powder and 370g of α-naphthol powder, the ratio of feed (mol ratio) is 1:2.0, stir evenly and add 150ml of methanesulfonic acid, React at 10°C for 15h, and stand at 10-15°C for 60h, then raise the temperature to 40°C, keep stirring for 9h, stand at room temperature for 14h, and room temperature to 40°C. Sampling and measuring liquid color content is 29.31%.

[0040] c. Separation and purification process:

[0041] Dissolve the dark green viscous reactant with 4.6L of absolute ethanol, and white insoluble matter precipitates out, and filter it. At this time, the filtrate is strongly acidic, adjust it with 430ml of 20% (w / w) NaOH (deionized water configuration) The pH value is neutral (tested with test paper), and a large amount of...

Embodiment 3

[0043] a. Pulverization process: phthalic anhydride and α-naphthol are pulverized into powder in advance;

[0044] b. Reaction process:

[0045] Add 190g of phthalic anhydride powder and 334g of α-naphthol powder into a 1L three-neck flask with stirring (stirring speed 225rpm), and the ratio (mol ratio) is 1:1.8. Stir evenly and add 180ml of methanesulfonic acid , reacted at 15°C for 9h, and stood at 25°C for 38h, then raised the temperature to 40°C, reacted for 9h under stirring, and took a sample to measure the liquid color content to be 27.63%.

[0046] c. Separation and purification process:

[0047]Use 4.6L of absolute ethanol to dissolve the dark green viscous reactant, white insoluble matter precipitates out, filter, at this time the filtrate is strongly acidic, adjust with 460ml of 20% (w / w) NaOH (deionized water configuration) The pH value is neutral (tested with test paper), and a large amount of insoluble matter precipitates out, which is slightly viscous. After f...

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Abstract

The invention discloses a preparation method of alpha-naphtholphthalein. The preparation method comprises the following steps of 1, a crushing process comprising pre-crushing phthalic anhydride and 1-naphthol into powder, 2, a reaction process, 3, a separation purification process comprising dissolving the viscous reactant by a solvent a, carrying out filtration, neutralizing the filtrate by an alkali solution, carrying out filtration, concentrating the filtrate to obtain a viscous liquid, and adding a solvent b into the viscous liquid, heating to boiling, carrying out cooling , carrying out filtration, adding deionized water into the filter cake, heating to boiling, carrying out filtration and washing, dissolving the filter cake by a solvent c, heating to boiling, carrying out strong resolving by deionized water, and carrying filtration and drying to obtain alpha-naphtholphthalein powder. The preparation method has simple processes and a high product yield, realizes high product purity and can be industrialized easily.

Description

technical field [0001] The invention relates to a preparation method of α-naphtholphthalein. technical background [0002] α-naphtholphthalein is also known as 1-naphtholphthalein, methyl-naphtholphthalein, 3,3'-bis(4-hydroxy-1-naphthyl)-1(3H)-isobenzofuranone, English name: α-Naphtholphthalein , 3,3-Bis(4-hydroxy-1-naphthyl)phthalide [0003] The structural formula is as follows: [0004] [0005] Its reaction principle is as follows: [0006] [0007] The disclosed preparation method is: 3.8 grams of phthalic anhydride and 7.0 grams of α-naphthol were reacted at 60° C. using 0.75 ml of concentrated sulfuric acid as a catalyst for 4 hours to obtain a viscous crude product. The sulfuric acid was diluted with a large amount of water and crushed to make the product into a Granular, then heated to 70°C with a large amount of 0.5% dilute alkali (NaOH) to dissolve the product, filter and separate the by-products, then adjust the pH with hydrochloric acid to precipitate t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D307/88
Inventor 骆小红刘孟李娜千昌富
Owner CHINA LUCKY FILM CORP