CH679043A5 - - Google Patents

Description

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CH 679 043 A5

description

Substituted glycidylanilines are a component of temperature-resistant epoxy resin systems and are used as coating materials for microelectronic components, as adhesives, as base material for reinforced epoxy resin materials and as a system component of photopolymerizable information recording materials.

It is known that substituted glycidylanilines according to formula V or VI

n-ch, -ch-ch0

X c \ / l

R, 0

Cv)

ch9-ch-ch "-n

X ✓ 1 f XQ R

'5 3

from the analog aniline derivative, cf. Formula I or II,

n-ch9-ch-ch0 »• 2 V / 2 Rx 0

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can be obtained by reaction with epichlorohydrin at elevated temperature. The synthesis is carried out in aromatic solvents, e.g. Toiuen, performed. The required dehydrohalogenation also takes place at higher temperatures (Polym. Bull. 14 (1985) 123). Other authors convert aniline derivatives with epichlorohydrin in ethanol-water mixtures to chlorohydrins according to formula III or IV.

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r

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n-ch9-ch-ch0-ci

I £ r L

rx oh

(III)

R

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R

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ci-ch2-

n-ch2-ch-ch2-ci civ)

rx oh

This reaction takes place in the boiling point of the solvent. The dehydrohalogenation also takes place here at temperatures of 50-80 ° C. (EP 239 804, EP 0 090 681).

It is also known that catalysts can be used in the dehydrohalogenation, e.g. quaternary ammonium salts are used (EP 0 143 075, EP 0 076 584, Journal of Applied Polymer Science 30 (1985) 2907). The glycidylanilines obtained in this way are obtained in higher yields and better quality than compounds which were prepared without a catalyst (EP 0 143 075).

Other authors synthesize substituted glycidylanilines by heating an aniline derivative with epichlorohydrin in the presence of a catalyst at 70 ° C for 24 h and performing the dehydrohalogenation with sodium hydroxide solution also in the presence of a catalyst at temperatures of 10-15 ° C (EP 76584).

Furthermore, it is described in the literature that aniline derivatives are reacted with epichlorohydrin in water / alcohol mixtures at the boiling point of the solvent. Dehydrohalogenation with sodium hydroxide takes place at approx. 10 ° C or room temperature in bulk.

The synthetic processes mentioned here have the following disadvantages:

- When using primary aromatic anilines, a certain proportion of monoglycidyl compounds is present in the reaction product. The presence of monoglycidyl compounds leads to discoloration of the product if stored for a long time. In addition, the storage time in the presence of such compounds is relatively short. Monoglycidyl compounds are particularly in the reaction product when the reaction is carried out in toluene.

- Other by-products that are formed at higher temperatures are derivatives of tetrahydroquinoline. These substances also contribute to the fact that the end product is strongly colored and has short storage times

- At higher temperatures, higher molecular weight, oligomeric compounds are preferably formed. The presence of oligomers leads to higher viscosity and less storage stability of the end product.

- If working in the presence of a catalyst, this must be removed almost quantitatively after the end of the reaction, since even traces of it can worsen the storage time of the end product. Other side reactions can also be accelerated by traces of catalyst.

- The presence of atmospheric oxygen leads to an oxidation of the aniline derivatives at higher temperatures, which is associated with an intensive discoloration of the reaction mixture.

The aim of the invention is to produce substituted glycidylanilines in a simple manner in relatively high purity.

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The invention has for its object to develop a simple process for the preparation of substituted glycidylanilines in relatively high purity. According to the invention, the object is achieved in that substituted anilines are converted to chlorohydrins with oxygen rejection and these are then dehydrohalogenated in the temperature range from -10 ° C. Substituted anilines of the formula I

R3, R4 mean:

H, alkyl with 1-6 C atoms, aralkyl with 1-6 C atoms in the aliphatic part, ester groups, these preferably being derived from aliphatic radicals with 1-6 C atoms or from phenolic esters, alkoxy with 1-6 C atoms, phenoxy, further primary, secondary or tertiary amino groups, where R 1 can denote H, alkyl having 1-6 C atoms, aralkyl having 1-6 C atoms in the aliphatic part, reacted with epichlorohydrin in a protic solvent Exclusion of air at a slightly elevated temperature in an interval of 35-50 ° C, to compounds of formula III

n-ch7-ch-ch2-ci (iii) r-. "0h where R 1, R 2, R 3, R 4 have the same meaning as in formula I and dehydrohalogenated them to give the corresponding glycidyl compounds of the formula V in ice cold in the temperature range from -10 ° C to 10 ° C. with the aqueous solution of a base,

where R 1, R 2, R 3, R 4 have the same meaning as in formula I and all amine hydrogens of the aniline derivative I are substituted by glycidyl groups corresponding to formula V by this process. Substituted anilines of the formula II

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where the substituents R 1, R 2, R 3, R 4, Rs are present, but R 2, R 3, R 4 have the same meaning as in formula I and Rs can have the same meaning as R 2, R 3 or R 4, where R 1 H, alkyl with 1 -6 O atoms, aryl or aralkyl with 1-6 C atoms in the aliphatic part, where X can be a covalent bond, an alkylene group with 1-6 C atoms, an alkylene arylene alkylene group with 1-6 C atoms in the aliphatic part an arylene group, a heteroatom such as O, SO2, reacted with epichlorohydrin in a protic solvent with exclusion of air at a slightly elevated temperature of 35-50 ° C. to give compounds of the formula IV,

X, Rt, Rg, R3, R4, R5 have the same meaning as in formula II and dehydrohalogenated them to the corresponding glycidyl compounds of formula Vt in ice cold at temperatures of -10-0 ° C. with the aqueous solution of a base,

where X, Ri, R2, R3, R4, Rs have the same meaning as in formula II. According to the invention, all amine hydrogens are substituted by glycidyl groups in the synthesis and the epoxides obtained according to formula V or VI are in sufficient purity for further use.

It is known from EP 0 143 075 that substituted glycidylanilines can be synthesized by reacting substituted aniline derivatives of the formula II in the presence of a catalyst salt at 60-90 ° C. with epichlorohydrin and then dehydrohalogenating them with sodium hydroxide solution at 70 ° C.

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Surprisingly, it was found that the reaction of epichlorohydrin with aromatic amines according to formula I or II to compounds according to formula III or IV under inert gas in a protic solvent takes place almost quantitatively at temperatures of 35-50 ° C., and thus the proportion of monoglycidyl compounds is very small and that the dehydrohalogenation with sodium hydroxide solution in ice cold 5 takes place without substantial formation of by-products. The desired glycidyl compounds of the formulas V and VI are already pure enough as raw products for many purposes. The mild reaction conditions apparently suppress the formation of oligomeric impurities, as is known that this process preferably takes place at higher temperatures.

In addition, it was found that working under inert gas contributes to the fact that the resulting crude products are almost colorless with a layer thickness of 2 mm. A catalyst can be dispensed with since the reaction proceeds completely even without it.

Due to the phase separation during dehydrohalogenation in the cold, numerous polar impurities remain in the aqueous phase. This effect increases the purity of the desired glycidyl derivative according to formula V or VI in the organic phase.

15 The epoxides of formula V or VI thus obtained have the advantage over those which are produced by conventional processes that the product is purer and thus the color is lighter and the storage stability is greater.

The product yield is also higher in some cases because the work was carried out under gentler conditions.

20 epoxides produced by this process can be used immediately for many polymer-specific reactions without further purification because their purity is sufficient.

Embodiments

25 Example 1

In a 1 liter flask, 3.1 moles of epichlorohydrin are added under inert gas (argon) at a temperature of 50 ° C to a mixture of 1.4 moles of aniline and 380 ml of abs. Ethanol added dropwise. After the addition has ended, the mixture is stirred at this temperature for a further 6 hours. The alcohol is then distilled off at 40-50 ° C. in a water pump vacuum. The residue is cooled to 0 ° C in an ice-salt bath. At this temperature, 2.8 mol of 45% sodium hydroxide solution are added dropwise within one hour so that the temperature in the flask does not exceed 2 ° C. The mixture is stirred for a further 2 hours. The reaction mixture is then poured into 500 ml of water and washed several times with a 5% sodium chloride solution. After this process, it is washed three more times with distilled water and the organic phase is dried over sodium sulfate. Distillation in an oil pump vacuum gave 80% yield of product which was colorless.

Boiling point in vacuo (0.5 Torr): Kpo, s = 145 ° C

40 epoxy content> 99.5%

Chlorine content <0.2%

If instead of inert gas under reduced pressure of p = 12 torr, 80% yield of reaction product is also obtained.

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Epoxy content> 99.5%

Chlorine content <0.2%

If p-toluidine was used instead of aniline, the yield of the product was 85%.

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Kp0.5 = 165 ° C epoxy content> 99.5%

Chlorine content <0.2%

55 If 2.8 mol of N-ethylaniiin is used instead of 1.4 mol of aniline, the corresponding product is obtained in 95% yield.

Epoxy content 99.5%

Chlorine content 0.2%

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Example 2

380 ml of absolute ethanol and 0.7 mol of 4,4-diaminodiphenylmethane are placed in a 1 liter flask under an inert gas atmosphere. During the reaction, a stream of argon is bubbled through the solution. 65 The mixture is heated to 50 ° C and at this temperature 3.1 mol of epichlorohydrin slowly

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added dropwise so that the temperature does not exceed 50 ° C. The mixture is stirred for a further 6 hours at this temperature. The mixture is then cooled to 0 ° C. and 2.8 mol of a 45% sodium hydroxide solution are added dropwise within 2 hours in such a way that the temperature in the flask does not exceed 2 ° C. After the addition has ended, the mixture is stirred at this temperature for a further 2 hours. Two phases are formed, the upper one, the organic one, being worked up further. For this, it is poured into 2 liters of water. This mixture is extracted with toluene, washed three times with a 2.5% sodium chloride solution and then extracted with distilled water until the aqueous phase is free of chloride ions. The organic phase is dried with sodium sulfate, and the excess toluene is removed on a rotary evaporator. A pale yellow, viscous oil with a

Yield 90%.

C 70.5% (calc. 71.09%)

H 7.1% (calc. 7.1%)

N 6.43% (calc. 6.63%)

If 2,2 (4,4'-diaminodiphenyi) propane is used instead of 4,4'-diaminodiphenylmethane, a yield of product of 80% is obtained.

If N, N-di-benzyl-4,4'-diaminodiphenyimethane is used instead of 4,4'-diaminodiphenylmethane, a yield of product of 80% is obtained.

Claims (3)

Claims 1. Process for the preparation of substituted glycidylanilines from substituted anilines by reaction with epichlorohydrin in a protic solvent and subsequent dehydrohalogenation with the aqueous solution of a base, characterized in that substituted anilines are converted to chlorohydrins with oxygen rejection and these are then in the temperature range —10— 0 ° C be dehydrohalogenated. 2. The method according to claim 1, characterized in that substituted anilines of the formula * 4 where Ra, R3, R4 are preferably H, alkyl having 1-6 C atoms, aralkyl having 1-6 C atoms in the aliphatic part, ester groups, these preferably being composed of aliphatic radicals having 1-6 C atoms or of phenolic esters derive, mean alkoxy with 1-6 C atoms, phenoxy, further primary, secondary or tertiary amino groups and Ri H, alkyl with 1-6 C atoms, aralkyl with 1-6 C atoms in the aliphatic part, reacted with epichlorohydrin , in a protic solvent with exclusion of air at a slightly elevated temperature in a temperature range of 35-50 ° C, to compounds of the formula JU $ 2 Ijl-CH2-CH-CH2-CI <111? Rl OH wherein Rt, R2, R3, and R4 have the same meaning as in formula i and dehydrohalogenated them to the corresponding glycidyl compounds of formula V in ice cold in the temperature range of -10-0 ° C with the aqueous solution of a base. 8th 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 CH679 043A5 n-ch2-ch-CH2 i Ri O t V î where Ri, R2, R3 and R4 have the same meaning as before. 3. The method according to claim 1, characterized in that substituted anilines of the formula II wherein the substituents Ri, R2, R3, R * and R5 are contained and Ri, Ra, R3, R4 have the same meaning as before and Rs have the same meaning as R2, R3 and R4 and where X is a covalent bond, an alkylene group with 1-6 C atoms, an alkylene arylene alkylene group with 1-6 C atoms in the aliphatic part, an arylene group, a hetero atom such as O, SO2 means, reacted with epichlorohydrin in a protic solvent with exclusion of air at a slightly elevated temperature of 35-50 ° C. to give compounds of the formula JV, where X, Ri, Rz, R3, R4 and Rs have the same meaning as in formula ü, and dehydrohalogenated them to the corresponding glycidyl compounds of formula Vi in ice cold at temperatures of -10-0 ° C. with the aqueous solution of a base, H2C - CH-CH2-N G Rj N-CH2-CH-CH2 CVIÎ O Rs r3 where X, Ri, R2, R3, R4 and Rs have the same meaning as in formula] l. 9