Comparison between Desheng's method of preparing luminol and several other preparation methods

Luminol is a commonly used chemiluminescence reagent. The color of its products is best white, followed by milky white, and then light yellow. Luminol developed and produced by Desheng is milky white powder, which is easily soluble in lye. It is also soluble in dilute acid, almost insoluble in water, and difficult to dissolve in alcohol. It will only show luminescence when it is used as a solution. At the same time, when we install this product, we need to use a light-shielding and well-closed container. The temperature should be guaranteed to be 0-5°C, and attention should be paid to avoid light and moisture, so as to ensure that the product inspection quality is more accurate and higher. Luminol has a wide range of uses. In addition to criminal investigation, it can also be used for immunochemiluminescence reactions, for the detection of sex hormones, drug abuse, and cardiovascular and reproductive diseases. In view of its application value and broad market prospects, the advantages of our company's patented preparation method compared with traditional preparation methods are worthy of attention.

Traditional preparation method:

(1) Using 3-nitrophthalic acid as the raw material, the cyclization reaction with hydrazine hydrate is carried out, and luminol is obtained by reduction with sodium hydroxide. The synthetic method has a simple process route, but the disadvantages are: 1. The first step is high reaction temperature and requires 225°C; 2. The purification is difficult. The first step requires high boiling point triethylene glycol as a solvent, which is difficult to remove. The reducing agent used in the second step will decompose and produce several inorganic impurities during the reaction process, which are difficult to remove; 3. The yield is low, only about 30%.

(2) Using 3-nitrophthalic acid as a raw material, the cyclization reaction is carried out with hydrazine sulfate, and luminol is obtained by reduction with sodium hydroxide. The synthesis method has been improved on Route 1, but the disadvantages are: 1. The highly toxic hydrazine sulfate is used; 2. The reaction temperature in the first step is 170 degrees, which is too high and requires high equipment; 3. The reaction produces a lot of In the waste liquid, the reducing agent used in the second step will decompose and produce several inorganic impurities during the reaction, which are difficult to remove.

(3) 3-Phthalic anhydride is used as raw material, nitrated with mixed acid to obtain 3-nitrophthalic acid, dehydrated with acetic anhydride to obtain 3-nitrophthalic anhydride, then hydrazinolysis, and finally iron powder reduction Get luminol. The shortcomings of the synthesis method are: 1. The synthesis route is longer; 2. The mixed acid nitrification produces a large amount of acidic waste liquid; 3. The reduction of iron powder results in a large amount of iron slag waste, which causes great environmental pollution.

Desheng preparation method:

The method of "a one-pot synthesis of luminol or isoluminol" developed by Desheng has obtained a patent. Compared with the prior art, its advantages and beneficial effects are obvious.

1) This method realizes that the three-step reaction is completed in the same pot, the intermediate product does not need any purification treatment, and the final product is directly obtained.

2) The method has simple synthesis route, mild reaction conditions, simple operation, and all the reagents required are conventional reagents, and the equipment required is conventional equipment, and the price is low. Therefore, the cost required for synthesis is low, and it is suitable for large-scale industrial production. .

3) The yield and purity of luminol and isoluminol synthesized by this method are high, the yields of luminol and isoluminol are all above 80%, and the HPLC (high performance liquid chromatography) purity is above 98% , Can fully meet the needs of industrialized production of products and market demand.