DE1220863B - Process for the preparation of 4,4'-diaminodiarylalkanes - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

C07c

German class: 12 q-1/02

Number: 1220 863

File number: F 44367 IV b / 12 q

Filing date: November 4, 1964

Opening day: 14th Wed 1966

It is known that 4,4'-diaminodiphenylalkanes by condensation of ketones with aromatic amines, especially aniline to produce aqueous hydrochloric acid with application of pressure at temperatures of about 15O ⁰ C in the presence of. According to this process, acetone and aniline give 2,2-bis- (4-aminophenyl) propane in a yield of only 13% of theory [Liebigs Annalen der Chemie, 472, p. 1 (1929), United States patent 2,794 822]. This is all the more understandable as it is known that quinoline derivatives are formed under the same conditions.

In contrast, the reaction of ketones with aromatic amines in the presence of small amounts of amine hydrochloride or ZnCl ₂ only leads to diaminodiphenylalkanes in a few cases. In this way it is possible to react acetone and acetophenone with tertiary amines such as N, N-dimethylaniline [Liebigs Annalen der Chemie, 242, p. 333 (1887)]. Under these conditions, primary aromatic amines condense to form anil or quinoline bodies. Thus is formed by heating acetophenone with aniline and aniline hydrochloride to 18O ⁰ C, a mixture of Acetophenonanil, Dypnonanil and 1,3,5-triphenyl- [Reports of the German Chemical Society, 43, p 2477; Liebigs Annalen der Chemie, 388, pp. 185 and 195], while the reaction of anhydrous aniline hydrochloride with acetone in a closed vessel leads to a quinoline derivative [reports of the German Chemical Society, 65, p. 1514 (1932)].

A process has now been found for the preparation of 4,4'-diaminodiarylalkanes by reacting ketones with salts of aromatic amines, in which the reaction is carried out under anhydrous conditions at normal pressure in the melt
4,4'-diaminodiarylalkanes

Applicant:

Paint factories Bayer Aktiengesellschaft,
Leverkusen

Named as inventor:

Dr. Heinrich Krimm, Krefeld-Bockum;

Dr. Arthur Botta,

Dr. Hermann Schnell, Krefeld-Uerdingen

leads, adding the ketones according to consumption. In the case of the implementation of acetone

ao with aniline hydrochloride, the formation of the quinoline derivative is almost completely suppressed.

Evidently there has been a prejudice to date to convert low-boiling ketones, such as acetone (bp 56 °), with high-melting amine salts, such as aniline hydrochloride (mp 199 °), in an open reaction vessel, ie at normal pressure. The advantage of the present pressureless process is according to the invention that you can keep the concentration of ketone in the reaction mixture as low as desired and thus suppress the formation of self-condensation products that z. B. in acetone and aniline via mesityl oxide to the quinoline derivative and in acetophenone to dypnone and 1,3,5-triphenylbenzene.
The process is exemplified using the reaction of acetone with aniline hydrochloride:

NH ₂ · HCl

melt

alkali

NH,

2HCl + H ₂ O

-NH ₂

609 589/324

3 4

For the process come aliphatic, cycloali- - - ■. · -, - ■ ·, -Example 2; ' . '. · ■■' ■ '
phatic, mixed aliphatic-aromatic and aromatic ketones into consideration. A melt of 1035 g (8MoI) aniline hydro-

Suitable amines are unsubstituted as well as in chloride, which are in a vertical tube of 40 cm

Core located by aliphatic, aromatic, halogen, hy- 5 height and 6.5 cm diameter, one leads

Droxy groups and alkoxy groups substituted pri- in the course of 3 ¹ V ₂ hours by one in the soil

mary, secondary and tertiary aromatic amines with attached tube 93 g (1.6 mol) of acetone in vapor form

free p-position. at 200 ° C with stirring. At the same time you lead

The acids used to form salts create a weak stream of hydrogen chloride through the

must not only have a high degree of acidity, io reaction mixture. Unreacted acetone as well

Instead, water that is still formed in the reaction to form salts with a preferred water is distilled off.

wise melting point below 250 ° C. 65 g of the supplied acetone are converted. Man

Preference is given to using hydrogen halides - the melt works as in Example 1 with 3 kg of ice

acids, especially hydrochloric acid, and aryl and 1 kg of 45% sodium hydroxide solution. The vacuum

sulfonic acids. 15 distillation of the reaction product gives 185 g

It is advantageous to proceed in such a way that (73% of theory) 2,2-bis- (4-aminophenyl) propane,

the ketone in liquid or vapor form - possibly with a _{b.p. 0j07} 180 to 191 ° C. Melting point after recrystallization

Inert gas mixed - slowly in a 2 to multiple lization from toluene 132 to 133 ° C.
Excess of such a salt of the aromatic

Amine - mainly in melt or solution - in Example 3
the extent to which it is consumed in the reaction

will. In an analogous manner to that described under Example 1,

The reaction temperature is generally 3900 g (30 mol) of aniline hydrochloride and 600 g

about 120 to about 250 ° C., preferably 150 to 220 ° C. (5 mol) acetophenone 983 g (68 ° / _? of theory) of the

Although the condensation according to the invention also 25 hitherto unknown l, l-bis (4-aminophenyl) -

runs without catalysts, depending on the um-1-phenyl-ethane. The connection can be established at Kp. _{0> 3}

catalytic additives would be used. Distill almost undecomposed at 231 to 238 ° C and has

Proton points or a melting point of 159 ° C are particularly suitable for this.
Lewis acids, e.g. B. HCl, H ₃ PO ₄ , P ₂ O ₅ , ZnCl ₂ , BF ₃
or activated clay. 30

be such additives that the melting temperature of Example 4
Reduce the reaction mixture. Show this effect

have the above-mentioned acidic catalysts, but According to the example 1 are employed at 215 ⁰ C

also phenols, or high-boiling polar solutions 60 g (0.5 mol) acetophenone ^ with 430 g (3 mol)

medium, e.g. B. nitrophenols, 2,4,6-trichlorophenol, di- 35 o-toluidine hydrochloride. 85 g (66.5%

chloronaphthalenes, nitrobenzene, nitrotoluene, nitro- the theory) l, l-bis- (4-amino-3-methyl-phenyl) -l-phe-

diphenyl. nyl-ethane having a boiling. _0/1 222-226 ⁰ C. m.p.

The work-up and isolation of the obtained 152 ° C. The compound was not yet known

4,4'-Diaminodiarylalkane is written in the usual way,
using alkali to release the 40th

Base from the amine salt obtained. The Diamino Example5
diarylalkanes can be purified by distillation under reduced pressure or by recrystallization

They may allowed to rise up to 15O ⁰ C for the production of plastics encryption 45 temperature. Man drips

Find a turn. add acetone while stirring vigorously to the extent that

like it by reaction with the N-methylaniline hydrochloride is consumed. After 14 hours are

Example 1 174 g (3 mol) of acetone reacted. The reaction

50 product is dissolved in 21 water and diluted with

3900 g (30 mol) of aniline hydrochloride are made strongly alkaline in sodium hydroxide solution. The organic layer is melted in a 6 l flask under nitrogen, the layer is taken up in methylene chloride and 290 g (5 mol) of acetone are slowly washed out several times with water while stirring. The solution course of 5 hours was added dropwise. The medium temperature is then evaporated, the excess of the melt sinks because of the gradually stronger 55 N-methylaniline distilled off in vacuo and the reflux of initially 200 to 185 ° C. The residue is dissolved in methanol. The 2,2-bis- (4-methyl melt on a mixture of 8 kg of ice and 3.5 kg of aminophenyl) - propane obtained in crystallized form. 45% sodium hydroxide solution. The organic layer is separated, yield 504 g = 66% of theory, melting point, and the aqueous phase is washed with 11 methylene 60 from 132 to 133 ^° C.
chloride stripped. The united organic

Phases are washed salt-free with distilled water. Example 6
and attracts solvent and excess aniline

in a vacuum. In the vacuum distillation of the back In 642 g (6 mol) of N-methylaniline is passed up to

Prior go 795 g (70.5% of theory), wherein Kp _{0;. 5} 65 saturation hydrogen chloride. After you get the

175 to 200 ⁰ C above. The temperature, which solidified on cooling, allowed it to rise to 150 ° C, dripping

2,2-Bis- (4-aminophenyl) -propane melts afterwards in the course of 3 hours under vigorous

Recrystallization from toluene at 133 ^° C. Stirring 98 g (1 mol) of cyclohexanone and holds

then another 1 hour at 150 ^° C. The hot melt is poured onto a mixture of 1.5 kg of ice and 1 kg of 45% strength sodium hydroxide solution, then the mixture is shaken well in the separating funnel and the organic phase is separated off. The excess N-methylaniline is stripped off in vacuo and the residue that remains is distilled. The main amount is at ₀ bp, ₅ = 197-203 ⁰ C. 198 g (67.4% of theory). After recrystallization, the 1,1 - bis - (4 '- N-methylamino - phenyl) - cyclohexane melts at 122 ^° C.

Claims (2)

Patent claims: 1. Process for the preparation of 4,4'-diaminodiarylalkanes by reacting ketones with Salts of aromatic amines, characterized in that the reaction carried out under anhydrous conditions at normal pressure in the melt, the ketones according to consumption. 2. The method according to claim 1, characterized in that the reaction in the presence of a Lewis acid is carried out. 609 589/324 7. £ 6 © Bundesdruckerei Berlin