Preparation method and application of p-toluenesulfonyl hydrazide_Kain Industrial Additive

Background and overview^[1][2]

p-Toluenesulfonyl hydrazide, also known as 4-methylbenzenesulfonyl hydrazide, is a white crystalline powder, easily soluble in alkali, soluble in methanol, ethanol and butanone, slightly soluble in water and aldehydes, insoluble in benzene and toluene . It is used as a foaming agent for natural rubber, synthetic rubber and various plastics to produce fine closed-cell structures in plastics and rubber products. The products have small shrinkage and high tear resistance. It is also an important organic synthesis intermediate. Used in organic synthesis such as medicine and pesticide production.

Preparation^[1]

At present, the synthesis method of p-toluenesulfonyl hydrazide is mainly produced by the reaction of p-toluenesulfonyl chloride and hydrazine hydrate (or hydrazine salt) in benzene medium. The process steps are as follows: add water to dilute hydrazine hydrate to 10% The aqueous solution is put into an enamel reaction kettle, and sulfuric acid is added under stirring to react to generate a hydrazine sulfate solution. After stirring and dissolving benzene and p-toluenesulfonyl chloride, add it to the reaction kettle and mix with hydrazine sulfate. Stir continuously at room temperature, and a condensation reaction occurs to generate p-toluenesulfonyl hydrazine. Because p-toluenesulfonyl hydrazide is insoluble in benzene and only slightly soluble in water, it precipitates as a solid. The hydrogen chloride produced during the reaction is extracted and absorbed with water to obtain hydrochloric acid as a by-product. After the formation reaction of p-toluenesulfonyl hydrazide is completed, stop stirring, filter the reaction product, and leave the filtrate to separate into layers. The upper layer contains benzene and can be recycled, and the aqueous layer recovers unreacted hydrazine sulfate. The filter cake is washed with water to remove acid and water-soluble substances, and then dehydrated and dried at about 60°C to obtain the finished product.

The shortcomings of existing technology are:

(1) Benzene was used as a solvent in the reaction. Benzene is a toxic and carcinogenic substance that is easily volatile and can be harmful to the human body. A small amount of leakage and volatilization of benzene during use will be harmful to human health and the environment. Cause damage and pollution;

(2) During the reaction process, extremely corrosive hydrogen chloride gas and hydrochloric acid will be produced, which requires high equipment. The by-product hydrochloric acid contains a small amount of benzene, which is difficult to remove, which limits the use of the by-product hydrochloric acid. Harmless treatment is difficult and expensive, and can easily cause environmental pollution;

(3) Current synthesis methods all use expensive hydrazine hydrate as raw material, with yields of only about 80% and high production costs.

CN201710303582.4 provides a new method for preparing p-toluenesulfonyl hydrazide with simple process, low equipment requirements, recyclable by-products, high yield, low production cost, and green and environmental protection. The technical solution adopted is: using p-toluenesulfonamide, acetonazine and water as raw materials, react at a certain temperature to synthesize p-toluenesulfonyl hydrazide. The ammonia and acetone generated during the reaction can be reused to prepare acetonazine. The reaction After completion, the precipitated solid material is centrifugally filtered, and the filter cake is washed and dried to obtain the finished product of p-toluenesulfonyl hydrazide.

The specific process steps of the method of the present invention are as follows: put p-toluenesulfonamide, acetonazine and water into the reaction kettle, start stirring, heat and raise the temperature to 80°C to 90°C for reaction, and introduce the gas generated by the reaction into the fine Distillation tower, extract acetone and recover ammonia at the top temperature of 55 ℃ ~ 60 ℃; take samples for analysis after 8 to 12 hours of reaction. When the content of p-toluenesulfonamide in the reaction solution drops to 1%, stop heating and end the reaction. , after the reaction kettle is cooled to normal temperature, the materials in the reaction kettle are centrifugally filtered. The filtrate containing acetonazine and p-toluenesulfonamide can be directly reused to prepare p-toluenesulfonyl hydrazide. After the filter cake is washed with water, the temperature is about 60°C. After drying, the finished product of p-toluenesulfonyl hydrazide is obtained.

Apply^[2]

1. Used in the synthesis of abiraterone acetate

Adopt the following technical solution: a synthesis method of abiraterone acetate, including the following steps:

A. Dissolve p-toluenesulfonyl chloride in toluene to obtain a concentration of solution X. Slowly add hydrazine hydrate into solution of cold water, stir, filter, and then wash with purified water 3-5 times, and dry at room temperature to obtain white p-toluenesulfonyl hydrazide crystals; B. Combine dehydroepiandrosterone, methanol, and p-toluenesulfonyl hydrazide , fully stir and dissolve at room temperature to obtain solution Y, add sulfuric acid, reflux in an oil bath at 60°C for 0-8 hours, and determine the reaction end point by TLC analysis;After completion, the solvent is removed by rotary evaporation, and a large amount of white precipitate appears. Add 0°C ice water, suction filter, and then wash with purified water 3-5 times. Dry at 50°C to remove the water to obtain a white solid, which is the dehydrogenation solution. Androsterone-17-p-toluenesulfonylhydrazone; C, dehydroepiandrosterone-17-p-toluenesulfonylhydrazone, 1,4-dioxane, lithium tert-butoxide, Pd2(dba)3, and Xphos After fully dissolving at room temperature, stir for 0-30 minutes, where the Pd2(dba)3 is added under nitrogen protection, then quickly add 3-bromopyridine, react in an oil bath at 80-110°C for 0-24h, and determine the end point of the reaction by TLC analysis; After the reaction is completed, add 0°C ice water, shake thoroughly, add 20 mL of ethyl acetate, separate the liquids, extract with ethyl acetate, combine the organic phases, dry over anhydrous sodium sulfate, filter, and rotary evaporate to remove the swirling liquid to obtain a light yellow solid. , recrystallize with n-hexane to obtain a white solid, namely 17-(3-pyridyl)-androst-5,16-dien-3β-ol; D. Add 17-(3-pyridyl)- Stir androsten-5,16-diene-3β-ol, diethyl ether and triethylamine evenly, add acetyl chloride slowly and dropwise, stir and react at room temperature for 0-5h, and determine the reaction end point; after the reaction is completed, filter with suction, and the filtrate is Activated carbon is decolorized and rotary evaporated to obtain a white solid, which is the finished product of abiraterone acetate.

2. Preparation of an elastic prosthetic material

A prosthesis is a medical device that replaces a limb, organ or tissue of the human body. CN201710738323.4 provides an elastic prosthesis material and a preparation method thereof. Made from the following components by weight: 65-85 parts of solid silicone rubber particles, 45-60 parts of polymethyl methacrylate, 36-48 parts of polytrimethylene cyclocarbonate, diisonon phthalate 25-30 parts of ester, 30-35 parts of phloroglucinol triglycidyl ether epoxy resin, 15-25 parts of dimethyl sulfoxide, 10-18 parts of triethylenetetramine, 10-15 parts of p-toluenesulfonyl hydrazide .

Compared with the existing technology, the beneficial effects of the elastic prosthetic material of the present invention are: the solid silicone rubber particles and polymethyl methacrylate in the components of the prosthetic material of the present application work together to take into account the prosthetic material. The elasticity and strength of the prosthetic material are improved by the addition of polytrimethylene cyclocarbonate, which improves the thermal decomposition temperature of the prosthetic material. The p-toluenesulfonyl hydrazide in the component can reduce the thermal decomposition temperature of the prosthetic material. The density makes the prosthetic material lighter and also helps to improve the breathability of the prosthetic material. The prepared elastic prosthetic material can be widely used in the field of medical plastic surgery.