DE1620415A1 - Process for the preparation of a new class of organic compounds - Google Patents

Description

Process for the preparation of a new class of organic compounds The present invention relates to a new class of organic compounds. ganic compounds and the production of organic isocyanates from the same. In particular, it relates to aliphatic polynitrile sulfites and polynitrile carbonates, which are characterized by the following formula: in which R is an aliphatic, including cycloaliphatic, hydrocarbon having 1-50 carbon atoms, preferably about 1-50 carbon atoms; 1 is S or C n is 1, 2 or 3, preferably 1.

The aliphatic hydrocarbon R can be saturated or unsaturated, straight or branched chain and with non-interfering groups, e.g. aromatic substituents, be sucstituted.

The hydrocarbon R is preferably alkyl, including.

Cycloalkyl or monoolefinic. The nitrile sulfite or nitrile carbonate groups can be attached to the same or different carbon atoms of the hydrocarbon R be bonded, but the hydrocarbon R preferably contains a nitrile sulfite or carbonato group at each end of the chain.

The alphatic nitrile sulfites and carbonates according to the invention are valuable intermediates or precursors in the manufacture of desirable chemicals. So you can z.;. are thermally decomposed to polyisocyanates. Polyisocyanates, such as diisocyanates, are often used in the manufacture of high molecular weight polymers through reaction of the polyisocyanates with polymerizable organic compounds, such as compounds with terminal, active hydroxyl and amine groups. Polyurethanes are z. B. usually by reaction of diisocyanates and polybasic Alcohols such as glycols.

The aliphatic polynitrile sulfites and polynit ri lcarbonate can also with basic materials to the corresponding amines or with acid to aliphatic Hydroxamic acids are hydrolyzed.

The decomposition of the aliphatic nitrile sulfite or carbonate too the corresponding aliphatic polysocyanates is carried out by heating the aliphatic Nitrile sulfites or carbonates to a temperature below the decomposition point of the desired aliphatic polyisocyanate product.

Since the decomposition is exothermic, there is a tendency that the reaction temperature gets too high very quickly. Therefore, means for evacuating or absorbing the Heat can be used to keep the temperature below the decomposition point of the desired aliphatic polyisocyanate product.

The temperature used will of course vary as a function on the decomposition temperature of the feed and the decomposition temperature of the special, aliphatic polyisocyanates. In most cases the temperature is up but usually between about 50-200 ° C, preferably about 75-15,000.

The decomposition is expediently carried out in the presence of an inert solvent, such as benzene, xylene, toluene, chlorobenzene, etc. or thionyl chloride or phosgene.

The ability of the invention aliphatic nitrile sulfites and carbonate, to form polyisocyanates when heated, is very advantageous because the aliphatic nitrile sulfites and carbonates in contrast to isocyanates in the absence are stable from water and are therefore easy to handle and store. There none active in the aliphatic nitrile sulfites and carbonates according to the invention Hydrogen, e.g. in the form of HCl, is present, and also not in the formed Decomposition products that would otherwise occur in the production of the Isocyanates could react, offers the use of an aliphatic nitrile sulfite and carbonate in the production of polyisocyanates a process that is not under reduced Yields and the separation and purification problems caused by by-products suffers from the starting materials of conventional processes in which active hydrogen is present. The use of aliphatic nitrile sulfites and carbonates in the production of isocyanates also offers a process that is not known which use azides, an advantageous process since, according to the invention, not the usual ones Risks of esplosion occur and work can be carried out more economically.

Aliphatic polynitrile sulfites and polynitrile carbonates are not yet has been manufactured. Beck describes in "Reports, Vol. 84 (1951) pages 688 to 689 however, the manufacture of methyl mononitrile carbonate says nothing about polynitrile sulfites or polynitrile carbonates. Furthermore, Knunyants et al in Proceedings of the Academy of Sciences of the USSR ", Vol. 127, No. 2, 1959 1,2,2,2-tetrafluoroethyl nitrile sulfite, but even they say nothing about any polynitrile sulfite or carbonate. aside from that Knunyants et al describe a mononitrile sulfite, the aliphatic radical of which is high contains reactive fluorine atoms, whereas the aliphatic polynitrile sulfites according to the invention and carbonates an aliphatic radical consisting only of carbon and hydrogen atoms contain.

In the preparation of the aliphatic nitrile sulfites and carbonates according to the invention, an aliphatic polyhydroxamic acid is reacted with thionyl chloride to form the nitrile sulfite or with phosgene to form the nitrile carbonate. Lipid polyhydroxamic acids which react with thionyl chloride or with phosgene to form the novel compounds according to the invention can be represented by the following formula: in which R and n have the meaning given for the structure of the aliphatic polynitrile sulfites and carbonates according to the invention.

Aliphatiache polyhydroxy acids, which act as reactants in the Production of the aliphatic polynitrile sulfites and polynitrile carbonates according to the invention are suitable are, for. B.: MalodihydroxaRic acid, Succinodihydroxamic acid, ßlutarodihydroxamic acid, Adipodihydroxamic acid, pimelodihydroxamic acid, suberodihydroxamic acid, azelodihydroxamic acid, Sebacodihydroxamic acid, fumarodihydroxamic acid, itacodihydroxamic acid, allylmalodihydroxamic acid, Allylsuccinodihydroxamic acid, Ierodihydroxam-. acid, cetylmalodihydroxamic acid, 1,6,9-decanetrihydroxamic acid, 1,3,6-heptane trihydroxamic acid, cyclohexyldihydroxamic acid, 4-bromo-1,6-hexanedihydroxamic acid, 3-hydroxyl-1,8-octanedihydroxamic acid and 2-chloro-1,9-nonanedihydroxyamic acid.

Aliphatic polynitrile sulfites or nitrile carbonates according to the invention include those corresponding to the above hydroxamic acids, such as Mab, succino, Glutaro-, Adipo-, Pimelo-, Subero-, Azelao-, Sebaco-, Fumaro-, Itaco-, Allylmalo-, sllylsuccino, xero and cetylialodinitrile sulfite or dinitrile carbonate; 1,6,9-decane and 1,3,6-heptane trinitrile sulfite or trinitrile carbonate; 4-bromo-1,6-hexane, 2-chloro-1, α-nonane and cyclohexyl dinitrile sulfite or dinitrile carbonate.

The temperature at which the aliphatic hydroxamic acid reaction is carried out and thionyl chloride or phosgene may be chosen depending on the particular one aliphatic hydroxamic acid can be varied; however, the response should be in everyone Fall below the decomposition temperature of the desired aliphatic nitrile sulfite or carbonates are carried out. Reflux temperatures can also be used as long as the reflux temperature of the particular mixture is below the decomposition temperature of the corresponding aliphatic nitrile sulfite or carbonate produced lies. The reaction temperature usually falls in a range up to about 90 ° C., often up to about 40-70 ° C., preferably up to about 300 C. The reaction can also can be carried out at temperatures of only about - 30 ° C. Usually the Reaction easily at atmospheric pressure, however, if necessary, over- or sub-atmospheric prints are applied.

Either the hydroxamic acid or the thionyl chloride or phosgene can be present in excess, but it is preferred that at least one stoichiometric Amount of thionyl chloride or phosgene is used, i.e. a ratio of at least one equivalent of thionyl chloride or phosgene per equivalent of hydroxamic acid. A large Excess thionyl chloride or phosgene is particularly preferred. The reaction can take place in the liquid phase, in many cases the alphatic hydroxamic acid reacts also in solid state. The alphatic hydroxamic acid is expediently first used in dissolved or slurried in an oxygen-containing organic solvent. Suitable oxygen-containing organic solvents are thionyl chloride or phosgene themselves and the normally liquid organic ethers, esters, furans, dioxanes etc. The preferred solvent is thionyl chloride or phosgene itself, and an excess thereof partially dissolves the aliphatic hydroxamic acid.

The reaction is often less than about half an hour, e.g. 15 minutes, or in about 5 - 20 hours, depending on the reaction temperature used depends and is indicated by the cessation of the evolution of hydrogen chloride. Normally is at least about half an hour to complete the reaction at temperatures necessary to reduce the side reactions. The reaction is usually right fast once the aliphatic hydroxamic acid is dissolved. With the lower ones The aliphatic dissolves at reaction temperatures Hydroxamic acid common slowly and can even go out of solution and redissolved in the course of the reaction will.

The aliphatic nitrile sulfite or carbonate can by suitable Means can be obtained from the resulting solution, e.g. B. by the obtained Filtered solution to remove unreacted starting materials and remove the filtrate then to remove unreacted thionyl chloride or phosgene and optionally The inert solvent used is subjected to reduced pressure, whereby the aliphatic Nitrile sulfite or carbonate is obtained as a crude product. Before filtering can the solution can also be cooled to crystallize out the product, which then is obtained as described. The raw product that depends on particular used aliphatic nitrile sulfite or carbonate be crystalline or liquid contains small amounts of high chlorine contaminants. A purer one, virtually chlorine-free product can be obtained by recrystallization, e.g. on a suitable Solvents such as dichloromethane, carbon disulfide (carbon disulfide), ethyl acetate, Thionyl chloride or phosgene or mixtures thereof.

A practically chlorine-free product can also be obtained by extraction or Washing with a hydrocarbon solvent can be obtained. For extraction Any normally liquid hydrocarbon solvent can be used, such as B.

Alkanes with 5-15 or more carbon atoms, aromatic solution medium, such as benzene, xylene, toluene, chlorobenzene, etc. At the extraction the minimum amount of solvent used is the actual amount used Amount depends on particular aliphatic nitrile sulfite or carbonate. Possibly can be used to achieve a practically chlorine-free aliphatic nitrile sulfite or -carbonates also use a combination of recrystallization and extraction processes be applied.

The thermal decomposition of the practically chlorine-free product delivers improved yields of a purer isocyanate product that is also practical is free from chlorine.

The following examples illustrate the present invention, without restricting them.

EXAMPLE 1 In a 300 cc round bottom flask fitted with an an CaCl2 drying tubes connected to the reflux condenser were 4.2 g (0.029 mole) puma dihydroxamic acid and 248 g (2.08 mole) thionyl chloride; the reaction mixture was refluxed with mechanical stirring for half an hour.

The. resulting solution was filtered and the thionyl chloride under removed under reduced pressure. There was thus a quantitative yield of crude fumaronitrile sulfite obtained with a melting point of 149-1500 ° C. (u dec.). Recrystallization from benzene gave chlorine-free white needles with a melting point of 150 ° C (u, decomp.) example 2 In a 500 ccm round bottom flask connected to a CaCl2 drying tube The reflux condenser was provided, 23.8 g (0.14 mol) of adipodihydroxamic acid and 495 g (4.16 mol) of thionyl chloride and the reaction mixture under mechanical Stirring heated to a maximum temperature of 550 C for 2 hours. The solution obtained was filtered and the thionyl chloride removed under reduced pressure. So became a quantitative yield of red adiponitrile sulfite obtained after recrystallization from pentane resulted in chlorine-free white needles with a melting point of 45.degree.

The infrared spectrum (Nujol mull) of the recrystallized material showed a distinct band at 6.19 microns, that for C = N stretching vibration (stretching vibration) is characteristic, and distinct, of eyclic sulphites characteristic absorption in the 8.13 Mieron range.

EXAMPLE 3 In a 500cc round bottom flask attached to a: A reflux condenser connected to the drying tube was provided, 28.0 g (0.121 Mol) sebacodihydroxamic acid and 495 g (4.16 mol) of thionyl chloride and the reaction mixture Maintained at a maximum temperature of 250 ° C. for 2 hours with mechanical stirring. The reaction mixture was filtered to give 5.9 g of starting material. The Ti: ionyl chloride was removed from the filtrate under reduced pressure to give a quantitative one Yield of crude sulfite based on the converted raw material.

The crude sebacodinitrile sulfite with a mp of 47-49 ° C was from Pentane recrystallized and gave chlorine-free white crystals with a melting point of 48 ° -50 ° C.

Analysis for C10H16N2O6S2 calc .: C to 37.05 H 4.94 N 8.65 S 19.75 found: C 37.89 R 5.50 N 7.29 The infrared spectrum (Nujol mull) of the recrystallized Materials showed a clear characteristic of a C = N stretching vibration Band at 6.19 microns and the absorption characteristic of cyclic sulfites in the 8.15 micron range.

EXAMPLE 4 In a 1 l round bottom flask connected to a CaCl2 drying tube connected reflux condenser was provided, were 13.2 g (0.075 mol) of adipodihydroxamic acid and 300 cc of tetrahydrofuran and the mixture with mechanical stirring about Heated for 3 hours to a maximum temperature of 410 C, whereby 121 g (12.0 mol) Phosgene were introduced.

The resulting solution was filtered and the solvents reduced under reduced pressure Pressure removed. So was a qualitative yield of crude adiponitrile carbonate obtained with a bp of 61-62 ° C. Recrystallization from a mixture of ether and pentane gave white, chlorine-free needles with an mp of 62-630 C.

Analysis for C8H8N2O6 calcd .: C 42.12 H 3.53 N 12.28 0 42.07 found: C 42.33 H 3.55 The infrared (Nujol mull) spectrum of the recrystallized material showed a clear characteristic of conjugated C-N stretching vibrations Absorption peak at 6.12 microns and a clear one typical of cyclic carbonates Band in the 5.48 micron range.

Example 5 In a 500 ccm round bottom flask attached to a CaCl2 drying tube connected reflux condenser was provided, 5.7 g (0.025 mol) of sebacodihydroxamic acid and 175 cc benzene and the mixture with mechanical stirring to a maximum Temperature of 55-75 ° C heated, with 28 g (0.28 mol) of phosgene were introduced. The resulting solution was filtered and the solvents under reduced pressure removed. Bo was using a quantitative yield of crude sebaconitrile carbonate obtained an rp of 42-45 ° C. Uncrystallization from a mixture of ether and Pentane gave white needles with an mp of 44-45 ° a.

The infrared spectrum (Nujol mull) of the recrystallized material showed a band characteristic of conjugated 0 = N at 6.13 microns and one typical peak for cyclic carbonates at 5.48 microns.

EXAMPLE 6 In a 300 cc round bottom flask immersed in a dry ice bath cooled from acetone and solid CO2 and connected to a Ca C12 drying tube The reflux condenser was provided, 4.2 g of Co, 029 mol) of fumarodihydroxamic acid and 248 g (2.51 mol) of phosgene and the reaction mixture with mechanical stirring Allowed to flow back for half an hour.

The resulting solution was filtered and the Fho.gen under reduced Pressure removed. There was thus a quantitative yield of crude fumaronitrile carbonate obtained with small amounts of impurities. Recrystallization from benzene gave chlorine-free fumaronitrile carbonate.

The nitrile carbonates - prepared according to the above examples and sulfites can be broken down into the corresponding polyisocyanates. Included can ii. Proceed as follows: In a 500 cci round disc with a A CaCl2 drying tube was connected to a reflux condenser, were 42 g (0.50 mol) of the fumarodinitrilaulfite prepared in Example 1 and 200 com @ -Dichlorobenzene and the reaction mix with mechanical stirring for 2 hours to reflux. The resulting solution was fractionally distilled and yielded 4.5 g (82%) chlorine-free trans-vinyl diisocyanate with a boiling point 745 mm 152-155 ° C.

The nitrile carbonates and sulfites produced in the other examples can be decomposed similarly.

Claims (8)

New claims: 1, compounds of the general formula in which R is an unsubstituted or substituted by non-interfering groups hydrocarbon radical with 1 to 50 carbon atoms, X is sulfur or carbon and n has the value of 1, 2 or 3. 2. Compounds according to # claim 1, characterized in that R 1 contains up to 30 carbon atoms and n = 1 3. Adiponitrile sulfite. 4. Sebacodinitrile sulfite. 5. Adiponitrile carbonate. 6. Sebaconitrile carbonate. 7. A process for the preparation of the compounds according to claims 1 to 6, characterized in that a polyhydroxamic acid of the general formula in which n has the above meaning and R represents an unsubstituted or non-interfering hydrocarbon radical having 1 to 50, preferably 1 to 30 carbon atoms, with thionyl chloride or phosgene. 8. The method according to claim 7, characterized in that the reaction is carried out in the liquid phase, with thionyl chloride or phosgene in excess Be used beyond the stoichiometric amount and the excess thionyl chloride or phosgene serve as a solvent for the polyhydroxamic acid, making the liquid Phase is created.