DE2524475A1 - NEW 1,2,3,5-OXTHIADIAZIN-2-DIOXIDE-4,6-DIONE - Google Patents

Description

New 1,2,3,5-oxthiadiazine-2-dioxide-4,6-diones

It is known that 4,6-diaryl-1,2 ₇ 3 _/ 5-oxthiadiazine-2-derivatives are obtained when nitriles are reacted with SO ₃ (Reports of the German Chemical Society, (1892), ^ 5, 461) . It is also known that cyanic acid esters, in the presence of SO, lead to 1,4-oxthia-2,5-diazine-4-dioxide derivatives (DT-OS 1 670 764, Angewandte Chemie, (1972), 1008).

It has now surprisingly been found that new N, N ¹ -substituted 1,2,3,5-oxthiadiazine-2-dioxide derivatives are obtained if isocyanates of the formula are used

R (N = C = O) _n

in the

R and η have the meaning given below,

₃ with liquid or gaseous SO, possibly diluted with inert gases or organic compounds in which SO is bound additive _3, optionally in an inert organic diluent, is reacted 8O ⁰ C in the temperature range of about -30 to +.

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The present invention relates to compounds of the formula

Ίϊ 0

in which

R represents an aliphatic hydrocarbon radical which may or may not have halogen or methoxy substituents a cycloaliphatic hydrocarbon radical or an araliphatic hydrocarbon radical and

η is an integer from 1 to 4.

The present invention also provides a process for the preparation of these new compounds, which is characterized by is that one isocyanates of the formula

R (N = C = O) _n

in which

R and η have the meaning given above at -30 to +80 ⁰ C with sulfur trioxide to react.

The present invention also relates to the use of these new compounds as latent hardeners for acid hardening resins.

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In the process according to the invention, as already indicated, the sulfur trioxide can be used in liquid or gaseous form / possibly diluted with inert gases or in the form of _{addition compounds which easily split off SO 3} with organic compounds capable of adding sulfur trioxide or in the form of simple solutions in inert solvents reach. Examples of organic compounds which are capable of reversible addition of sulfur trioxide are pyridine, dioxane, tetrahydrofuran, diethyl ether or dimethylformamide. Suitable inert solvents are in particular chlorinated hydrocarbons such as methylene chloride, dichloroethane or tetrahydrofuran or sulfur dioxide. It is particularly useful to use sulfur trioxide in gaseous form diluted with an inert gas such as nitrogen.

Reaction partners in the process according to the invention for the sulfur trioxide are isocyanates of the formula R (NCO), in which R and η have the meaning given above. In the process according to the invention, preference is given to mono- or diisocyanates are used (n. = 1 or 2), but monoisocyanates (n = 1) are particularly preferably used. Preferably R is an aliphatic hydrocarbon radical with 1 to 6 carbon atoms, a cycloaliphatic hydrocarbon radical with 5 to 10 carbon atoms or an araliphatic hydrocarbon radical having 7 to 8 carbon atoms. Particularly preferred in the case of η = 1, R stands for an aliphatic hydrocarbon radical with 1 to 6 carbon atoms, a cyclohexyl or benzyl radical; in the case of η = 2 for the remainder, as obtained by removing the isocyanate groups from hexamethylene diisocyanate, 1-isocyanato-3,3, S-trimethyl-S-isocyanatomethyl-cyclohexane or one of the isomeric xylylene diisocyanates is obtained.

The principle of the process according to the invention can, however, also be transferred to those isocyanates R (NCO) which are any

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Substituents which are inert under the reaction conditions such as dialkylamino, acylamino, nitro, aroxy, acyloxy, carbonyl, Carboxyl, carboxylic acid ester, carboxamide, sulfonyl, Sulfonic acid ester / sulfonic acid amide, acyl, cyano, rhodanide, Have alkyl mercapto, aryl mercapto or acyl mercapto groups. The process according to the invention can in principle also be carried out with those isocyanates R (NCO) in which R stands for one Halogen or alkoxy substituted cycloaliphatic or araliphatic Hydrocarbon residue. Isocyanates containing heterocyclic rings could in principle also be used in the case of the invention Processes are used provided that at least one aliphatically or cycloaliphatically bound isocyanate group is present.

Examples of isocyanates R (NCO) suitable for the process according to the invention are methyl isocyanate / ethyl isocyanate / n-hexyl isocyanate, n-dodecyl isocyanate, n-stearyl isocyanate, 6-chlorohexyl isocyanate, cyclohexyl isocyanate, 2-norbornyl methyl isocyanate, benzyl isocyanate, methoxymethyl isocyanate, methoxymethyl isocyanate, ethylene diisocyanate, dimethyl isocyanate, tetramethylene diisocyanate, tetra methyl isocyanate , Cyclobutane-1,3-diisocyanate, cyclopentane-1,3-diisocyanate, cyclohexane-1,3- and 1,4-diisocyanate, 1-isocyanato-3 _f 3,5-trimethyl-5-isocyanatomethyl-cyclohexane, 2 , 4- and 2/6-hexahydrotoluylene diisocyanate, hexahydro-1,3- and -1,4-phenylene diisocyanate, perhydro-2,4 ¹ - and -4,4'-diphenylmethane diisocyanate, and ortho-, meta-, para-xylylene diisocyanate, or also tri- or tetraisocyanates, such as 4,4 '^^' - triisocyanato-tricyclohexylmethane or 2,2 '^^' - tetraisocyanato-S ^ '- dimethyl-dicyclohexylmethane.

Particularly when using monoisocyanates can in the invention Process, two different isocyanates can be used simultaneously or in succession.

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In the process according to the invention, the addition of the sulfur trioxide onto two isocyanate groups then gives rise to the groups according to the invention new compounds of the formula mentioned above. The preferred or particularly preferred compounds according to the invention are those which arise from the preferred or particularly preferred isocyanates mentioned.

In the method according to the invention, the amount of the to be used Sulfur trioxide preferably dimensioned so that 'that per mole of isocyanate R (NCO) about 0.5 to 0.6 mol of sulfur trioxide are used.

Carrying out the reaction according to the invention is very simple. The output to be sulfonated isocyanate is dissolved in general initially introduced in one of the above-exemplified inert solvent, and, preferably mixed at -30 to + 80 ° C -20 to +20 ⁰ C with sulfur trioxide or sulfur trioxide adduct intimately. It is possible to initially charge the isocyanate as well as the sulfur trioxide and to add the respective reactant. The compounds according to the invention either precipitate, after which they are isolated by suction or they remain dissolved in the diluent, in which case they can generally be obtained as crystalline substances by distilling off the solvent.

The new compounds according to the invention, in particular the isocyanate-free compounds according to the invention, are valuable latent hardeners for aminoplast and phenoplast resins such as melamine-formaldehyde resins, urea-formaldehyde resins or phenol-formaldehyde resins or their mixtures with polyether or Polyester polyols. The resins combined with the new compounds are distinguished by a high curing rate at elevated temperature, but longer pot lives than resins combined with conventional hardeners at room temperature. A particular advantage of the invention compounds containing isocyanate groups over known acid hardeners is that the Le A 16 449 '- 5 - released on heating

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Diisocyanate itself also acts as a hardener. Combined acid-isocyanate curing can therefore be carried out.

The compounds according to the invention obtained from polyisocyanates are also used as reactive polyisocyanates, which with active hydrogen-containing low or high molecular weight compounds to form heterocyclic-containing polyurethanes or polyureas or polyurethane polyureas react, which are opposed to ring opening in the heat with others Isocyanate-reactive hydrogen atoms containing Connections are networkable.

Because of their polar character or their ability to produce sulfur trioxide The products obtained from di- or polyisocyanates and sulfur trioxide are particularly suitable for splitting off carbon dioxide for the production of inorganic-organic composite systems, e.g. in combination with aqueous alkali silicate solutions and / or Filler (suspensions).

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example 1

57 g (1 mol) of methyl isocyanate are dissolved in 300 ml of dry 1,2-dichloroethane. On the surface of this vigorously stirred mixture, an S0 ₃ / nitrogen stream is fed in at -5 to + 5 ° C, which is obtained by evaporation at 130 ° C of 22 ml (0.525 mol) of freshly distilled S0_ in a nitrogen stream. The amount of nitrogen is regulated in such a way that no more SO2 escapes from the reaction vessel. The clear reaction mixture obtained is evaporated, 79 g (= 80% crude yield) of pale yellow oil remaining. Distillation at 90 to 10 ° C / 0.3 m Hg gives the N, N'-dimethyl-1,2,3,5-oxethiadiazine-2-dioxide-4,6-dione

as a white crystalline product which can be recrystallized from chloroform. F. «54 to 56 ° C

The structure of this product and the following is determined by elemental analysis and physical analysis methods (IR, KR, MS spectra).

Analysis: Ber .: C% 7th H % N % O % S% , 5 Found: 24, 7th 3, 1 14th , 4 41 / 3 16 , 4 24, 3, 1 14th , 4 41 , 7 16

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Spectroscopic investigations:
IR spectrum: those for grouping

-N

characteristic intense absorptions are at 1730 cm " ¹ and 1810 cm" ¹

MS spectrum: the mol peak m / e = 194 is also the base peak. The fragmentation process clearly corresponds to the specified structure.

KR spectrum in CDCl,: singlet at 3 »41 ppm

Example 2

Analogously to Example 1, from 66 g (0.5 mol) of benzyl isocyanate and 10.2 ml (0.25 mol) of freshly distilled SO ₃ , after evaporation of the solvent, an oil residue with an insoluble solid content is obtained. After the latter had been separated off, 48 g (= 56% yield) of the N, N'-dibenzyl-1,2,3,5-oxathiadiazine-2-dioxide-4,6-dione remained

C ₆ H ₅ -CH _{2 -N}

«Α Λ»,

CH ₂ -C ₆ H ₅

as viscous 03 that completely crystallizes out over time.

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F: 82-84 ⁰ C (CCl ^)

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Analysis: C 96

calc .: 55.5
found: 55.5

E% N % O %

4.0 4.1

8.1 8.3

23.1 22.6

5 %

9.3 9.2

The IR spectrum shows the two characteristic bands at 1735 and 1810 cm " ¹ .

In the MS. Spectrum, the mol peak at m / e = 346 and the fragments _/ derived therefrom are in agreement with the structure indicated.

Example 3

Analogously to Example 1, 0.5 mol of meta-xylene diisocyanate is obtained and 0.25 moles of SO- that

CH ₂ -NCO

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with 40% yield as a solidified oil, which under vacuum from 150 ° C the starting diisocyanate is split off again.

Example 4

Analogously to Example 1, there is obtained from 0.5 mol of 1,6-hexamethylene diisocyanate and 0.25 moles of SO ^ that

OCN- (CH ₀ ) _- N 2 6,,

with 80% yield as a viscous oil. Example 5

Analogously to Example 1, 0.5 mol of 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate is obtained and 0.25 mol of SO- following derivative in 50% yield.

OCN-H ^ C

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Example 6

88 g (1 mol) of methoxyethyl isocyanate are reacted according to the method described in the example with 21 ml (0.5 mol) of SO ₃ in 300 ml of 1,2-dichloroethane, the IR spectrum of the clear reaction mixture obtained indicating the presence of the following derivative

0 0

H ₀ CO-CH ₀ -N 0

3 2,,

can be closed.
Example 7

To prove the usability of compounds of this substance class The following tests were carried out as latent hardeners:

1) The mixtures of 30 parts by weight of a commercially available, acid-curable melamine-formaldehyde resin and 70 parts by weight of a polyester polyol with OH number 173 made from phthalic acid / isophthalic acid / 1,6-hexanediol / trimethylolpropane

and one part by weight of the compound of the invention Example 1 or one part by weight of p-toluenesulfonic acid applied as a 1 mm thick layer on two steel plates. The pot life of these resin mixtures was approximately at room temperature 60 hours with the catalyst prepared according to Example 1 and about 36 hours with para-toluenesulfonic acid.

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2) The same resin mixtures with only about 0.5 parts by weight of the two catalysts cure at 100 ° C. in the same period of time from 1 hour.

Example 8

114 g of methyl isocyanate are added to a solution of 80 g of sulfur trioxide in 300 ml of dried methylene chloride with cooling at -20 ° C added dropwise. The mixture is then allowed to stir for 3 hours at room temperature. After removing the solvent in Vacuum leaves an oil that is based on the addition of carbon tetrachloride and petroleum ether crystallized. Yield: 165 g (85% of theory). Melting point: 54.degree

The following were produced in the same way:

from ethyl isocyanate: N, N'-diethyl-1,2,3,5-oxa-thiadiazine

2,2-dioxide-4,6-dione

Bp 85 ° C / 0.2 torr

from n-propyl isocyanate: N, N'-di-n-propyl-1,2,3,5-oxa-thiadiazine

2,2-dioxide-4,6-dione

Bp 90 ° C / 0.25 torr

from cyclohexyl isocyanate: N, N'-di-cyclohexyl-1,2,3,5-oxa-thiadia-

zin-2,2-dioxide-4,6-dione

Example 9

If, following the procedure of Example 8, first one mole of methyl isocyanate and then 1 mole of n-propyl isocyanate are added to the initially charged sulfur trioxide solution, N-methyl-N ¹ -n-propyl-1,2,3,5-oxathiadiazine-2 is obtained , 2-dioxide-4,6-dione. B.p .: 100 ° C / 0.4 Torr.

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Claims (3)

Claims ; j
1> Compounds of the formula ⁰ J in which R for an optionally halogen or methoxy substituent having aliphatic hydrocarbon radical or a cycloaliphatic hydrocarbon radical or an araliphatic hydrocarbon radical and η is an integer from 1 to 4. 2) Process for the preparation of the compounds according to claim 1, characterized in that isocyanates of the formula R (N = C = O) in which R and η have the meaning given in claim 1 at -30 to +80 ⁰ C to react with sulfur trioxide. 3) Use of the compounds according to claim 1 as latent hardeners for acid-hardening synthetic resins. Le A 16 449 - 13 - 609852/0982