CH422794A - Process for the preparation of addition compounds - Google Patents

Description

  

  
 



  Process for the preparation of addition compounds
Isocyanates react extremely poorly with ketenes. From phenyl isocyanate and diphenyl ketene, the production of diphenylmalonic acid phenylimide has only succeeded in low yield at 2200 C.



   It has now been found that by reacting ketenes of the formula
EMI1.1
 where R1 and R2 can be the same or different and have the meaning of hydrogen, alkyl or aryl radicals, with sulfoisocyanates of the formula R-SO2-N = C = O, where R is halogen or a substituted or unsubstituted, in particular aliphatic or aromatic hydrocarbon radical , in the presence of an inert solvent in smooth reaction can obtain addition products which contain one mole of sulfoisocyanate per mole of ketene. The compounds are obtained during the reaction in both monomeric and polymerized form.

   The monomeric compounds that are crystallized correspond to the formula
EMI1.2

Particularly suitable radicals R of the sulfoisocyanates are: the halogens with atomic weights of up to 36, namely fluorine and chlorine, also alkane radicals and aryl radicals, such as. B. the radicals derived from benzene, naphthalene, toluene, dimethylbenzene, methylnaphthalene and the corresponding higher homologues as well as the corresponding derivatives substituted by halogens, primarily chlorine or bromine, or by nitro groups.

   The following sulfoisocyanates may be mentioned as examples:
Benzene sulfoisocyanate, toluene sulfoisocyanate,
Trimethylbenzenesulfoisocyanate,
Nitrotoluene sulfoisocyanate,
Chlorobenzenesulfoisocyanate,
Dichlorobenzene sulfoisocyanate,
Naphthalene sulfoisocyanate, chloromethylnaphthalene sulfoisocyanate,
Methanesulfoisocyanate,
Fluorosulfoisocyanate,
Chlorosulfoisocyanate.



   As ketenes of the formula
EMI1.3
 Particularly suitable for the preparation of the addition compounds are those whose radicals R1 and R2 are hydrogen, a lower alkyl radical or a phenyl radical. The following ketenes may be mentioned as examples: methyl ketene, dimethyl ketene, ethyl ketene, diethyl ketene, methyl ethyl ketene, propyl ketene, phenyl ketene, diphenyl ketene and methylphenyl ketene.



   The preparation of the reaction products is preferably carried out by combining the two components in an inert solvent or else introducing the ketene, if it is gaseous, into the sulfoisocyanate dissolved in a solvent with stirring.



   Suitable inert solvents are those which are inert to ketene, remain liquid at the reaction temperature and at the same time are capable of dissolving sulfoisocyanates. For example, low molecular weight chlorinated aliphatic hydrocarbons such as methylene chloride, chloroform, Te trachlorkohlen material, trichlorethylene, P erchlorethylene, methyl chloroform and. Ä., in question. In addition, acid esters, e.g. B. ethyl acetate, open and / or cyclic; aither, such as diethyl ether.



  Dioxane, tetrahydrofuran, can be used as solvents. Since in most cases the compounds react at room temperature with a strong heat release, additional heating is not necessary. Rather, it is usually expedient to dissipate the heat of reaction by cooling. This applies in particular to the reaction of halosulfoisocyanates with ketene. Here you will work at temperatures below 0 C in order to avoid decomposition of the reaction products, since in particular the compounds in which the radical R has the meaning of a halogen atom are unstable at room temperature and decompose with elimination of sulfur dioxide. In most cases, temperatures of about 70 to about 250 ° C. can be maintained during the reaction.

   The choice of the reaction temperature is practically insignificant for the actual implementation; rather, it is primarily dependent on the resistance of the reaction products. If the products are stable at higher temperatures, they can also be used at higher temperatures than specified. There is practically no limitation in the direction of lower temperatures, provided the reaction medium remains liquid.



   The monomeric products usually crystallize out of the solution, while the polymerized products formed at the same time remain in the solution and can easily be isolated after filtration of the solution by distilling off the solvent.



  If the compounds are derived from sulfoisocyanates which contain a hydrocarbon radical, the monomeric form can be purified by recrystallization.



   The products of the process are valuable intermediates which, since they are very reactive substances, can be used directly for further reactions. The polymeric addition products e are used to treat textiles.



   Example I 98.5 g (0.5 mol) of p-toluenesulphoisocyanate are dissolved in 300 ml of methylene chloride. Ketene is passed into this solution at −10 ° C. with stirring until nothing. more is recorded. The crystal slurry obtained is filtered off with suction and dried.



  50 g of crude p-toluenesulfomalonimide and 66 g of polymeric addition product are obtained by evaporating the mother liquor. By recrystallizing the monomeric crude product from chloroform, 15 g of the pure substance can be obtained as colorless needles with a melting point of 1250 ° C. (with decomposition).



   Example 2
54 g (0.25 mol) of p-chlorobenzenesulfoisocyanate are dissolved in 150 ml of chloroform and ketene is passed into the solution at -300 ° C. with stirring until nothing is absorbed. Working up the reaction product in the manner described in Example 1 leads to 30 g of crude p-chloro-benzenesulfomalonimide and 32 g of polymeric addition product. By recrystallizing the monomeric crude product from acetone, 10 g of analytically pure substance with a melting point of 1010 ° C. (with decomposition) are obtained.



   Example 3
70.5 g (0.5 mol) of chlorosulfoisocyanate are dissolved in 200 ml of chloroform, and 0.5 mol of ketene is introduced into this solution at -500 ° C. with stirring. The addition product crystallizes out and can be isolated at low temperature. At room temperature it decomposes with elimination of sulfur dioxide.



   Example 4
62.5 g (0.5 mol) of fluorosulfoisocyanate are dissolved in 200 ml of chloroform and 0.5 mol of ketene is introduced into the solution at -50 ° C. with stirring.



  The colorless, crystalline addition product can only be isolated at low temperature and decomposes at room temperature with charring.



   Example S.
46 g (0.2 mol) of naphthalene sulfoisocyanate are dissolved in 300 ml of ethyl acetate and ketene is passed into the solution at 0 ° C. with stirring until nothing is absorbed. A yellow solution is formed from which colorless crystals separate out after a while. The reaction product is worked up as in Example 1. 25 g of naphthalenesullomalonimide are obtained as colorless crystals which decompose above 1000 ° C., and 27 g of polymeric addition product.

 

Claims (1)

PATENT CLAIM Process for l: Production of addition products, characterized in that ketenes of the formula EMI2.1 where R1 and R2 can be the same or different and have the meaning of hydrogen, alkyl or aryl radicals, with sulfoisocyanates of the formula R-SO2-N = C = O, where R is halogen or a substituted or unsubstituted hydrocarbon radical, in the presence of inert solvents implements. SUBClaim Process according to patent claim, characterized in that the resulting monomeric compounds are separated from the polymeric ones.