CH285365A - Process for the preparation of a monocyclic aromatic symmetrical triisocyanate. - Google Patents

Description

  

  Process for the preparation of a monocyclic aromatic symmetrical triisocyanate. The present invention relates to a process for the production of a monocyclic aromatic symmetrical triisocyanate, namely benzene-1,3,5-triisocyanate, which is used in the textile and rubber industries as an auxiliary substance and also as an intermediate product, e.g. . B. for the production of new aromatic urethanes and new aryl urethanes can be used.



  The process according to the invention for the preparation of the new monoeyclic aromatic triisocyanate is characterized in that the trilydrochloride of the 1st, 3,5-triaminobenzene is in an inert, volatile, organic diluent.

   suspended in the absence of water and phosgene is passed into this suspension at a temperature not below 85 ° C. under such conditions that the liberated hydrogen chloride is removed, phosgene being passed in until the formation of the triisocyanate has ended. is.



  The reaction temperature] is preferably between 90 and 130 C.



  The inert volatile diluent. is preferably removed from the reaction product obtained by distillation, the reaction mixture being secured against the ingress of moisture.



  The resulting solid product can be distilled with little decomposition under reduced pressure and purified in this way or by recrystallization, since it is soluble in ordinary inert organic solvents.



  It has been shown that the reaction takes place in stages, the intermediate product being the hydrochloride of the corresponding aminoaryl chlorocarbonamide and an aryl trichlorocarbonamide, which are not readily soluble in the organic solvents used.

   The end of the reaction can therefore usually be determined by the fact that the reaction mixture forms a clear solution. If desired, the elimination of the hydrogen chloride can be promoted by working with. the phos- o-en passes an inert gas through the reaction mixture.



  In order to facilitate the separation of the triisocyanate from the volatile solvents mentioned, it is advisable to use solvents which have a boiling point that does not rise above 160 ° C. have, for example, hydrocarbons, halogenated hydrocarbons or ethers, in particular toluene, xylene, ligroin, tetrachloroethane, ortho-ehlortoluene, anisole,

          Dioxane, 1VIonochlorbenzol or mixtures of one of these solvents with, for example, ethylene dichloride or benzene.



  The benzene-1,3,5-triisocyanate produced by the process according to the invention is a highly reactive compound. It reacts with alcohols to form new irethanes, with water to form a primary aromatic amino compound and with ammonia or primary aliphatic amines in C,

  waiting for water to rain with the formation of new aryl ureas or aryl alkyl ureas. If the new triisocyanate is applied to cellulose with the exclusion of moisture and subsequently subjected to heat treatment, a chemical reaction takes place which changes the surface properties of the textile material.



       If desired, dry hydrogen chloride can be introduced into the suspension of the trihydrochloride in the volatile inert solvent, for example at room temperature, before the reaction with phosgene is started at an elevated temperature.



       Example: 10 parts of 1,3,5-triamino benzene trihydrochloride are suspended at 95 ° C. in 1.00 parts of monochlorobenzene and a slow stream of dry phosgene is passed through the cream mixture, which is stirred and increased. the temperature slowly to 120 C. After about 2 to 4 hours the suspended solid substance disappears. The developed hydrogen chloride is diverted.

   The monochlorobenzene is distilled off from the solution obtained, if desired under reduced pressure, and the residue consisting of benzene-1,3,5-triisoeyanate is distilled at about 20 mm pressure. On cooling, the distillate forms long colorless needles with a melting point of 85 ° C. in a yield of about 60% of theory.



  If the benzene-1,3,5-triisocyanate is dissolved in boiling absolute alcohol and the solution is allowed to cool, crystals of the corresponding triurethane with a melting point of 1.92 ° C. are obtained. If the benzene-1,3,5-t.riisoci-anat is dissolved in alcohol-free, anhydrous ether and the solution is treated with an excess of anhydrous ammonia in the form of a solution in the same solvent, the corresponding triearbamide is obtained, which melts at a temperature above 350 C. Both substances are also new compounds.

 

Claims (1)

PATENT CLAIM Process for the production of a mono-eyclic aromatic symmetrical triisocyanate, namely benzene-1., 3,5-triisoeyanats, characterized in that the trihydrochloride of 1,3,5-triatnino-benzene in an inert , volatile, organic diluents are suspended in the absence of water and phosgene is introduced into this suspension at a temperature not below 85 C under such conditions, that the liberated hydrogen chloride is removed, the introduction of phosgene takes place until the formation of the triisocyanate has ended. is. The benzene-1,3,5-triisocyanate melts at 85 C. SUBClaims 1. Process according to patent claim, characterized in that a reaction temperature of 90 to 130 C is used. 2. The method according to claim and dependent claim 1, characterized in that the inert, volatile, organic diluent is separated off by distillation. 3. A method according to claim and the dependent claims 1 and 2, characterized in that the triisocyanate is purified by distillation under reduced pressure. Process according to patent claim and dependent claims 1 and \ ?, characterized in that the triisoeyanate is purified by recrystallization from an inert organic solvent. 5. Process according to patent claim, characterized in that the inert, volatile, organic diluent has a boiling point of no more than 160 C.