CH639392A5 - PHENOXYALKYL-, THIO-PHENOXYALKYL- AND PYRIDYLOXYALKYL-TRIALKOXY-SILANES AND METHOD FOR THE PRODUCTION THEREOF. - Google Patents

Description

The invention relates to new phenoxyalkyl-, thiophenoxyalkyl- or pyridyloxyalkylsilanes of the general formulas Ia or Ib:

ZR2Si (OR3)

[Ia]

or

OR3Si (OR3)

[Ib]

in which R1 is -NH2, -NR4H, -NR'î, -CHO, -CN, -COR4, CI, Br, J, -SO2R4, -SOR4, -NÔ2, -SR4 or -OR4, R2 is methylene or alkylene with 3 to 12 carbon atoms, the substituents R3 and R4 independently of one another are alkyl, cycloalkyl, aryl, alkaryl or aralkyl, the alkyl group of these substituents R3 or R4 each containing 1 to 12 carbon atoms, and Z representing oxygen or sulfur.

The invention further relates to a process for the preparation of the above-mentioned new phenoxyalkyl-, thiophenoxyalkyl- or pyridyloxyalkylsilanes, which is characterized in that essentially equimolar amounts of an alkali compound of the general formulas IIa or IIb:

[IIa]

or

[Hb]

in which M represents an alkali metal, with a halo-alkylsilane of the general formula

XR2Si (OR3) 3 (III)

in which X is chlorine, bromine or iodine, reacted with one another by means of the alkali compound and the silane under practically anhydrous conditions at temperatures between room temperature and 200 ° C. in a liquid reaction medium consisting essentially of a liquid hydrocarbon boiling between 40 and 5 200 ° C. and a dipolar aprotic liquid to react and thereby keep the reaction medium obtained at a temperature of 40 to 200 ° C for a time sufficient for practically complete conversion of the alkali compound and the silane into the desired phenoxyalkyl, thiophenoxy-10 alkyl or pyridyloxyalkyl silane, the reaction medium is filtered to isolate the desired silane and the solvent is evaporated from the liquid phase.

The compounds according to the invention are functionally substituted phenoxyalkyl-, thiophenoxy-alkyl- or pyridyloxyalkylsilanes of the general formulas given above. The substituent R1 present on the phenyl group is defined above. Amino groups are preferred for this, since the class of this compound 20 can be used in a particularly wide variety of ways. The substituent R1 can be present in the ortho, meta or para position to the oxygen atom. The phenoxy, thiophenoxy or pyridyloxy group is attached to the silicon atom through an alkylene group, which may be methylene or a higher alkylene group of 3 to 12 carbon atoms, which is either linear or branched. Compounds in which R2 stands for ethylene, however, are already so unstable in the presence of only trace amounts of aqueous acids or bases that they are worthless for all practical purposes. In addition to the alkylene group mentioned above, the silicon atom is also bound to three groups of the general formula -OR3.

The compounds according to the invention can be prepared simply by reacting an alkali salt, preferably the sodium salt, of the desired phenol, thiophenol or hydroxypyridine with a haloalkylsilane of the general formula XR2Si (OR3) 3. This reaction is highly exothermic and is preferably carried out under an inert atmosphere and in the absence of even trace amounts of water, since water is known to react easily with trialkoxy- and triaryloxysilanes to form polymeric products. The reaction medium is a mixture of at least one liquid hydrocarbon boiling between 40 and 200 ° C. and a dipolar 45 aprotic liquid, such as dimethyl sulfoxide, N, N-dimethylformamide, tetramethylurea or hexamethyl-phosphoramide. The trialkoxyhaloalkylsilane is preferably gradually added to a reaction medium containing the respective alkali salt. After this addition has ended and any exothermic reaction has ceased, the reaction mixture should expediently be heated to from 70 to approximately 150 ° C. for several hours, so that the reactants are virtually completely converted to the desired phenoxyalkyl, thio-phenoxyalkyl or pyri-55 dyloxyalkyltrialkoxysilane is. The compounds according to the invention, many of which are colorless high-boiling viscous oils, are soluble in the reaction medium and can be isolated therefrom readily by removing the above-mentioned liquid hydrocarbon and dipolar solvent. Some of these compounds can also become dark when exposed to light or air for long periods.

The trialkoxyhalosilanes 65 required as starting materials for the preparation of the compound according to the invention are either commercially available or can be obtained by reacting the corresponding haloalkyltrihalosilane of the general formula X'R2SiX5, in which X1 and X2 are chlorine, bromine or iodine, with an alcohol of the general

639392

4th

Formula R3OH, which contains 1 to 12 carbon atoms. The haloxytrihalosilane required for this can be prepared by reacting a haloalkene, such as allyl chloride, with a trihalosilane of the general formula HSiXj at ambient temperature in the presence of a platinum catalyst. Methods for producing the silanes required as intermediates are generally known. A detailed discussion of the reaction conditions to be used here can therefore be dispensed with.

Examples of phenols and thiophenols which can be used to prepare the compounds according to the invention are aminophenols and aminothiophenols, the amino group of which is arranged in the ortho, meta or para position to the hydroxyl group, the isomeric hydroxybenzaldehyde and the isomeric esters of hydroxybenzoic acid. and Mer-captobenzoic acids, the alcohol residue of which contains 1 to 12 carbon atoms. If the alcohol contains a phenyl group, the number of carbon atoms is preferably 7 to 1B. Other substituents that may be present on the phenyl group are apparent from the description and the claims.

The functionally substituted silanes according to the invention are suitable as coupling agents for glass fiber reinforced composites, flocculants for water purification and sizing for glass fibers or fabrics. By reacting the compounds according to the invention with liquid hydroxyl- or alkoxy-terminated organopolysiloxanes, if appropriate together with additives, it is possible to form elastomeric products which are suitable as coating materials, sealants and molding compositions. Compounds in which the substituent R1 stands for amino or dialkylamino (-NHa or -NR;) give waxes and polishes a detergent resistance.

The invention is illustrated by the following examples. All parts and percentages contained therein are based on weight, unless stated otherwise.

Example I

3- (p-aminophenoxy) propyltrimethoxysilane

A glass reactor is mixed with 60 g (0.55 mol) of p-aminophenol, 43.28 g of a 50% aqueous solution of sodium hydroxide (0.54 mol of NaOH), 112 ml of dimethyl sulfoxide and 120 ml of toluene. The reaction mixture obtained is then heated to boiling under a nitrogen atmosphere for 6 hours in order to remove all the water present by azeotropic distillation. The reaction mixture is then allowed to cool to about 75 ° C. and, at this point, 109 g (0.55 mol) of 3-chloro-propyltrimethoxysilane are added dropwise with stirring. During this addition, the temperature of the reaction mixture spontaneously rises to 85 ° C. The temperature of the reaction mixture is kept at 75 to 85 ° C. by heating and corresponding control of the rate of addition. When the addition is complete, the reaction mixture is heated to 115 ° C. for 16 hours, whereupon it is allowed to cool and filtered to remove any solid material that may be present. The solvents are then removed under a pressure of about 15 mm Hg at a temperature of about 60 ° C. Then the pressure is reduced to 3 to 4 mm Hg and the material boiling at 170 to 180 ° C is obtained. This fraction, which weighs 70 g, is then distilled in a fractionation column, collecting 50 g of a distillate which boils at 175 to 177 ° C. under a pressure of 3 mm Hg. The colorless liquid thus obtained contains 10.19% silicon and 5.20% nitrogen. The calculated values for 3- (p-aminophenoxy) propyltrimethaxysilane are 10.33% silicon and 5.17% nitrogen. The IR and NMR spectra of the product are consistent with the proposed structure.

Example 2

Preparation of 3- (m-aminophenoxy) propyltrimethoxysilane

The general procedure described in Example 1 is repeated 5 by using a corresponding reaction vessel with 300 g (2.75 mol) of m-aminophenol, 560 ml of dimethyl sulfoxide, 600 ml of toluene and 216 ml of a 50% aqueous solution of sodium hydroxide (2, 70 moles of NaOH). The water present in the reaction vessel is removed by azeotropic distillation under a nitrogen atmosphere at a temperature of 120 ° C. The temperature of the reaction mixture is then reduced to 90 ° C. and kept at about this value with the gradual addition of 545 g (2.75 mol) of 3-chloropropyltrimethoxysilane. After the addition, which takes 2 hours, the reaction mixture is heated to boiling temperature for 16 hours. The product obtained is then obtained as described in Example 1 and fractionally distilled. The fraction boiling at 178 to 180 ° C under a pressure of 3 mm Hg is collected and gives 630 g (85% yield) of material. The IR and NMR spectra of the product obtained confirm the proposed structure of the formula:

A vapor phase chromatogram of the product obtained gives a purity of over 98%.

Example 3

Preparation of 3- (p-formylphenoxy) propyltrimethoxysilane

The general procedure described in Example I is repeated, with a corresponding reaction vessel containing 62.2 g (0.55 mol) of p-hydroxybenzaldehyde, 112 ml of dimethyl sulfoxide, 120 ml of toluene and 43.2 g of a 50% aqueous sodium hydroxide solution Contains 0.54 mol NaOH. All the water present is removed by azeotropic distillation at a temperature of about 110 to 115 ° C. The reaction mixture is heated to boiling temperature, 109 g (0.55 mol) of 3-chloropropyltrimethoxysilane being gradually added. To isolate the 3- (p-formylphenoxy) propyltrimethoxysilane obtained as a product, the reaction mixture is isolated, the solvents are removed from the liquid phase obtained under reduced pressure and the solid obtained is subjected to fractional distillation. The fraction boiling at 208 ° C. and a pressure of 3 mm Hg is collected (based on the silane, the product yield is 85%). The IR and NMR spectra of the product obtained confirm the proposed structure of the formula:

OCH— (O) —10CH2CH2CH2Si (OCK3) 3

The vapor phase chromatogram of the product gives a purity of over 98%.

Example 4

Preparation of 3- (m-diethylaminophenoxy) propyltri-methoxysilane

The general procedure described in Example 1 is repeated and a corresponding reaction vessel is filled with 90.75 g (0.55 mol) of m-diethylaminophenol, 112 ml of dimethyl sulfoxide, 120 ml of toluene and 43.28 g of a 50% strength aqueous solution

15

20th

2S / Q \ _OCH2CH2CH2SKOCH3) 3

NH;

30th

35

40

45

55

60

65

Sodium hydroxide solution charged. All water present in the reaction vessel is removed by azeotropic distillation. The reaction mixture is then allowed to cool to 80 ° C. and at this point 109 g (0.55 mol) of chloropropyltrimethoxysilane are gradually added over a period of 2 hours. During the addition, the temperature of the reaction mixture increases to 88 ° C. After the addition has ended, the temperature of the reaction mixture is kept at 80 ° C. for 16 hours by appropriate heating. The reaction mixture is then allowed to cool and then filtered. The liquid phase obtained is evaporated under a pressure of 5 mm Hg to remove toluene and dimethyl sulfoxide. The pressure in the reaction vessel is then reduced to 2 mm Hg, and the 3- (m-diethylamino-nophenoxy) propyltrimethoxysilane obtained as the product is collected at a temperature of 185-187 ° C. A corresponding vapor phase chromatogram shows that the product obtained is 97% pure.

Example 5

Preparation of 3- (3-pyridyloxy) propyltrimethoxysilane

5 639 392

The general procedure described in Example 1 is repeated, a corresponding reaction vessel being charged with 52.3 g (0.55 mol) of 3-hydroxypyridine, 112 ml of dimethyl sulfoxide, 120 ml of toluene and 43.2 g of a 50% strength aqueous sodium hydroxide solution . The water present in the reaction vessel is removed by azeotropic distillation over a period of 64 hours. During this time, the temperature of the reaction mixture is kept at 85 to 105 ° C. The reaction mixture is then kept at a temperature of 95 ° C. and 109 g of 3-chloropropyltrimethoxysilane are gradually added. This temperature is maintained for 7 hours, whereupon a corresponding vapor phase chromatogram of the reaction mixture shows that the reaction has practically ended. The reaction mixture is filtered and the diluents present (toluene and dimethyl sulfoxide) are evaporated at a pressure of 5 mm Hg. The 3- (3-pyridyloxy) propyltrimethoxysilane obtained as a product is collected at a temperature of 142 ° C. under a pressure of 1 mm Hg. A corresponding 20 vapor phase chromatogram shows that this product has a purity of 97%.

B

Claims (3)

639392 PATENT CLAIMS 1. Phenoxyalkyl-, thio-phenoxyalkyl- and pyridyloxy-alkyl-trialkoxysilanes of the general formulas Ia or Ib: or or R4 each contains 1 to 12 carbon atoms, and Z represents oxygen or sulfur, characterized in that essentially equimolar amounts of an alkali compound of the general formulas IIa or IIb: ZR2SiCOR3) 3 [la] io OR2 Si COR3) 3 [Ib] [Ha] or [IIb] in which R1 stands for -NKh, -NR4H, -NRÏ, -CHO, -CN, -COR4, CI, Br, J, -SO2R4, -SOR4, -NCh, -SR4 or -OR4, R- methylene or alkylene with 3 to 12 carbon atoms, the substituents R3 and R4 independently of one another are alkyl, cycloalkyl, aryl, alkaryl or aralkyl, where the alkyl group of these substituents R3 or R4 each contains 1 to 12 carbon atoms, and Z represents oxygen or sulfur. 2. Silane according to claim 1, characterized in that R1 represents -NH2, -NRl or -CHO. 3. Silane according to claim 1, characterized in that R2 stands for n-propylene. 4. silane according to claim 1, characterized in that R3 is alkyl having 1 to 4 carbon atoms. 5. Silane according to claim 4, characterized in that R3 is methyl. 6. Process for the preparation of phenoxyalkyl-, thio-phenoxyalkyl- and pyridyloxyalkylsilanes of the general formulas Ia or Ib: ZR2Si (OR3) [Ib] or OR ^ Si (OR3) [Ib] in which R 'is -NH2, -NR4H, -NRl, -CHO, -CH, -COR4, Cl, Br, J, -SO2R4, -SOR4, -NCh, -SR4 or -OR4, R2 is methylene or alkylene with 3 to 12 carbon atoms, the substituents R3 and R4 independently of one another are alkyl, cycloalkyl, aryl, alkaryl or aralkyl, the alkyl group of these substituents R3 in which M represents an alkali metal, with a halo-2s genalkylsilan of the general formula XR2Si (OR3> (III) in which X is chlorine, bromine or iodine, reacted with one another by the alkali compound and the silane under practically water-free conditions at temperatures between room temperature and 200 ° C. in a liquid reaction medium consisting essentially of a liquid hydrocarbon boiling between 40 and 200 ° C. and a 3s dipolar aprotic liquid to react and thereby hold the reaction medium obtained over a period of time sufficient to practically completely convert the alkali compound and the silane to the desired phenoxyalkyl-, thiophenoxy-alkyl- or pyridyloxyalkylsilane at a temperature of 40 to 200 ° C. , the reaction medium is filtered to isolate the desired silane and the solvent is evaporated from the liquid phase. 7. The method according to claim 6, characterized in that one uses compounds in which R1 45 represents -NH2, -NR4H or -CHO. 8. The method according to claim 6, characterized in that compounds are used in which R2 is p-propylene. 9. The method according to claim 6, characterized in that one uses compounds in which R3 Alkyl with 1 to 4 carbon atoms. 10. The method according to claim 9, characterized in that one uses compounds of formula III in which R3 is methyl. 55 11. The method according to claim 6, characterized in that compounds of formula III are used in which X is chlorine. 12. The method according to claim 6, characterized in that compounds of formula Ilaund IIb 60 used, where M stands for sodium. 13. The method according to claim 6, characterized in that the dipolar aprotic solvent used is dimethyl sulfoxide, N, N-dimethylformamide, tetramethylurea and / or hexamethylphosphoramide. 65 14. The method according to claim 6, characterized in that one carries out the reaction between the alkali compound and the silane under an inert atmosphere. 15. The method according to claim 6, characterized 3rd 639392 shows that compounds are used in which R2 means propylene.