31 results about "Para-trifluoromethylaniline" patented technology

The invention discloses a method for recycling wastes of trifluoromethyl phenylamine kettle residues. The method comprises the steps of 1) vacuum distillation: by taking the trifluoromethyl phenylamine kettle residues as raw materials, adding inorganic alkali according to the proportion of 2-3% of the mass of the trifluoromethyl phenylamine kettle residues, performing vacuum distillation to obtain a light-component mixture containing m-trifluoromethyl phenylamine and p-trifluoromethyl phenylamine; and 2) vacuum rectification: adding the inorganic alkali into the light-component mixture obtained in the step 1), and performing rectification to obtain m-trifluoromethyl phenylamine and p-trifluoromethyl phenylamine respectively. According to the method disclosed by the invention, a polymerization phenomenon during the process of distillation and rectification is effectively prevented by adopting the inorganic alkali; the method is simple in operation process and easy in industrial production; and by adopting the technical scheme of the method, the discharge of pollutants of the production process is reduced, and the comprehensive recycling of the solid wastes is realized.

The invention relates to a preparation method of teriflunomide. The preparation method comprises the following steps: mixing cyano acetyl chloride, p-trifluoromethylaniline and an acid-binding agent according to the molar ratio of 1:(1-3):(8-11), and reacting to obtain 2-cyano-N-(4-trifluoromethyl-phenyl)-acetamide; mixing 2-cyano-N-(4-trifluoromethyl-phenyl)-acetamide, acetyl chloride and an acid-binding agent according to the molar ratio of 1:(1-5):(1-5) of reaction materials, and reacting to obtain teriflunomide. The process has the advantages that the raw materials are easily available, the reaction condition is mild and the yield is high, and the preparation method is suitable for industrial production.

The invention relates to a synthetic method of p-trifluoromethylaniline; p-chlorobenzotrifluoride and liquid ammonia generate an ammonolysis reaction to generate the p-trifluoromethylaniline under the action of a catalyst and an acid-binding agent; according to portion by weight, the components of the catalyst is: cuprous chloride of 1 to 10 portions, potassium fluoride of 2 to 30 portions and phase transfer catalyst of 5 to 30 portions; the adding amount of the catalyst is 8 to 70 percent of the p-chlorobenzotrifluoride (mass); the synthetic method of the invention adopts an effective compound catalyst to provide a synthetic scheme which has higher one way conversion rate and is economically practical in industry for the synthesis of the p-trifluoromethylaniline; the price of the catalyst used in the synthetic process is lower; furthermore, an organic solvent and the phase transfer catalyst can be recycled and reused; the manufacture cost is low; no waste water is discharged during the whole technique process; and the synthetic method of the invention is friendly to the environment.

The present invention discloses the production process of p-trifluoromethyl aniline. P-trifluorotoluene and liquid ammonia are reacted in the presence of alcohol and catalyst to obtain p-trifluoromethyl aniline. The catalyst may consist of ferrocene, triphenyl phosphor, potassium fluoride, ammonium tetrabutyl bromide. The present invention has high efficient composite catalyst used, single pass conversion rate up to 66 % and yield up to 90 %. The organic solvent may be used circularly, the excessive liquid ammonia may be prepared into ammonia water, the catalyst may be regenerated and reused, and the process has no waste water exhausted.

The present invention discloses 2, 6-dichloro-p-trifluoro methyl aniline preparing process, which includes the first reaction of 3, 4, 5-trichloro trifluoro toluene and fluoride salt in solvent to produce 3, 5-dichloro-4-fluoro trifluoro toluene, and the subsequent reaction of 3, 5-dichloro-4-fluoro trifluoro toluene and liquid ammonia or ammonia water to obtain 2, 6-dichloro-p-trifluoro methyl aniline. The process has 3, 4, 5-trichloro trifluoro toluene as the side product from p-chloro trifluoro toluene producing process adopted, lowered production cost, no use of acid matter and less corrosion of the equipment.

The invention provides a preparation method of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole. The preparation method takes p-trifluoromethylaniline as a raw material, carries out diazotization reaction and forms a ring with ethyl 2,3-dicyanopropionate under weakly acidic conditions; feeds an appropriate amount of chlorine gas into the ring compound for chlorination , by adjusting the pH decarboxylation to obtain the product 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl) pyrazole. The preparation method of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole of the present invention has simple operation, good chlorination selectivity and few side reactions 1. The product yield is high, and the reaction conditions are mild, which is conducive to realizing industrialization; the average yield of the method is not less than 95%, and the product purity is more than 99.50%.

The invention provides a method for preparing carbonyl fluoride from p-trichloromethylphenyl isocyanate. The method is a new one in which the carbonyl fluoride is safely and effectively obtained by reacting hydrogen fluoride and phenyl isocyanate; and the method can ensure that the reaction proceeds towards the direction of generating the carbonyl fluoride maximally. The method provided by the invention comprises the following steps: in the presence of the phenyl isocyanate and the excessive hydrogen fluoride, performing a first reaction on the hydrogen fluoride and the phenyl isocyanate at a low temperature; performing heating to perform a second reaction; collecting a p-trifluoromethyl aniline product; and performing cooling to collect the liquid hydrogen fluoride, introducing the uncondensed gas into a rectification tower, performing rectification, and performing separation to obtain hydrogen chloride and the carbonyl fluoride. The method provided by the invention can ensure high reaction yield, high product purity, mild reaction conditions and favorable safety; and on the basis of producing the carbonyl fluoride, the hydrogen fluoride, the hydrogen chloride and the p-trifluoromethyl aniline can be produced simultaneously, and no pollutant is discharged, thereby meeting environmental requirements.

The invention relates to a new method for preparing p-trifluoromethylaniline by performing high pressure ammonolysis. P-trifluoromethyl chlorobenzene serving as a raw material is subjected to high-temperature high pressure ammonolysis reaction in a solvent under the action of a catalyst, liquid ammonia and an acid-binding agent to generate p-trifluoromethyl phenylamine; the catalyst is a mixture of cuprous chloride and copper powder; the acid-binding agent is one or two of inorganic base mixtures of sodium hydroxide and the like, or one or two of organic base mixtures of pyridine and triethylamine; and the solvent is one or two of mixing solvents of methanol, ethanol, polyethylene glycol 300-3,000 and N,N-dimethylformamide. The method has the advantages that the inorganic base, serving as the acid-binding agent, with low cost and easy availability is adopted, the loss of liquid ammonia in the reaction process is greatly reduced, and the production efficiency is improved; and the catalyst can be prepared from organic solvents with the cost as low as that of ethanol and less harm, so that the generation of hydrolysis side reaction is avoided, the purity of the product is high and the quality is high; and raw materials without being totally reacted can be recycled.