DE1178068B - Process for the production of halogenated iminodibenzylene. - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school KL: "C07d

German class: 12p -5

Number: 1178 068

File number: G 31009 IVd / 12 ρ

Filing date: November 25, 1960

Date of delivery: September 17th, 1964

The invention relates to a method of manufacture of halogenated iminodibenzyls of the general formula

Process for the production of
halogenated iminodibenzylene

in which X is a chlorine or bromine atom. It has been found that the 3-haloiminodibenzyls (3-halogen-10,11-dihydro-SH-dibenzlb.flazepine) obtained in a simple manner by referring to compounds of the general formula

CH ₂ - H ₂ C

NH

II

Hydrogen, if appropriate under elevated pressure, in the presence of a hydrogenation catalyst and 1 mole of an inorganic or organic base is allowed to act.

Depending on the catalyst used, hydrogenation is carried out at pressures between 1 and 80 atmospheres and at reaction temperatures between room temperature and 100 ^{° C.} Raney nickel at pressures of 10 to 80 atmospheres and reaction ^{temperatures between 20 and 50 °} C. and noble metal catalysts, such as palladium, at room temperature and normal pressure, are preferably suitable as catalysts. The bases used are in particular alkali metal hydroxides and amines, such as triethylamine, which are used, for. B. as solutions in methanol or ethanol to the solution of the starting materials. Suitable solvents for the latter are, for. B. methanol and ethanol, meanwhile, the solution volume can be significantly reduced if you use dioxane instead, in which the starting materials are much more soluble. As a solvent can also be, for. B. tetrahydrofuran, benzene and toluene can be used. The dehalogenation is terminated after approximately 1 mol of hydrogen has been consumed. If there is a device for taking samples from the autoclave, the course of the reaction can also be followed on the basis of the neutralization of the added base. The hydrogenating dehalogenation of aromatic or heterocyclic halogen compounds with Raney nickel in the presence of alkali is already known. When treating applicant:

J. R. Geigy A. G., Basel (Switzerland)

Representative:

Dr. F. Zumstein,

DipL-Chem. Dr. rer. nat. E. Assmann

and Dipl.-Chem. Dr. R. Koenigsberger,

Patent Attorneys, Munich 2, Bräuhausstr. 4th

Named as inventor:
Dr. Henri Dietrich,
Birsfelden (Switzerland)

Claimed priority:

Switzerland of November 26, 1959 (81096)

p-dichlorobenzene with Raney nickel and alkali will 50% benzene next to 44% unchanged p-dichlorobenzene, but no significant amount of the monochlorine compound (Chemical Reports, Vol. 91 [1958], pp. 1376-1379). It was therefore not foreseeable that 3,7-dichloro- or 3,7-dibromo-iminodibenzyl is in good yield to 3-chloro or 3-bromo-iminodibenzyl would dehalogenate.

The starting materials of the general formula II for the process according to the invention are 3,7-dichloroiminodibenzyl and 3,7-dibromoiminodibenzyl. The former compound can be made from 2,2'-diamino-4,4'-dichlorodibenzyl according to the z. B. in the German patent specification 1000 820, the USA.-patent specification 2 800 470, the British patent specification 777 546 and the French patent specification i 167 669 and the second-mentioned compound in an analogous manner from 2,2'-diamino-4,4 '-dibromodibenzyl are produced.

The halogeniminodibenzyls obtained according to the invention are intermediates for the preparation of medicinal products.

The following examples are intended to illustrate the process according to the invention in more detail explain. Parts therein mean parts by weight.

409 687/316

example 1

To a solution of 264 parts of 3,7-dichloroiminodibenzyl in 600 parts by volume of dioxane are 56 parts of potassium hydroxide in 60 parts by volume of methanol and Given 75 parts of Raney nickel. Then at 30 to 45 ° C and 50 atmospheres hydrogen pressure hydrogenated until the hydrogen uptake is approximately 100% (about 48 hours). The catalyst is filtered off and the filtrate is evaporated to dryness. The residue is taken up in ether, washed with water, dried the ethereal solution over sodium sulfate and evaporated. The out a mixture of iminodibenzyl, 3-chloroiminodibenzyl and 3,7-dichloroiminodibenzyl The residue is fractionally distilled in a high vacuum and yields the following fractions:

1. bp OO8 128 to 135 ° C;

2. Kp.o, 08l35 to 141 ⁰ C;

3. Bp. o.8 142 to 145 ° C;

4. Piston residue.

The iminodibenzyl enriched in fraction 1 is separated off by crystallization from methanol; the added 3-chloriminodibenzyl remains in enriched form in the mother liquor A.

The 3,7-dichloroiminodibenzyl present in fraction 3 in addition to 3-chloroiminodibenzyl is through Separated crystallization from methanol; the 3-chloroiminodibenzyl remains in enriched form in the mother liquor B.

Fraction 2 contains 3-chloroiminodibenzyl contaminated with iminodibenzyl. She will be with the Mother liquors A and B combined and distilled again in a high vacuum:

a) Bp. o.9 108 to 115 ° C;

b) Kp.o, o9ll6 to 12PC;

c) Bp. o.9 122 to 127 ° C;

d) low piston residue.

Fraction b) crystallizes from gasoline or petroleum ether. Repeated recrystallization from gasoline provides 70 to 80 parts (30 to 35% of theory) of pure 3-chloroiminodibenzyl with a melting point of 87 to 89.degree.

Example 3

3.7 Dichloriminodibenzyl is hydrogenated according to Example 1 or according to Example 2 and the material to be hydrogenated is worked up according to Example 1. The fraction obtained after the first high vacuum distillation (corresponding to fraction 2 in Example 1), in which the majority of the 3-chloroiminodibenzyl formed is located, is dissolved in acetyl chloride and acetylated under reflux for 2 hours. After evaporation of the acetyl chloride and neutral washing of the evaporation residue of the residue from ether-petroleum ether or ether-methanol is fractionally crystallized, and S-acetyl-S-chloriminodibenzyl, mp 126 ° C from the coexisting 5-Acetyliminodibenzyl (F. 90 ⁰ C ) is separated.

Equal parts of 5-acetyl-3-chloriminodibenzyl and potassium hydroxide are used in 10 parts by volume of ethylene glycol heated under reflux for 4 hours, then 1 part by volume of water is added, still Boiled for 1 hour, cooled, diluted with 50 parts by volume of water and etherified. The ethereal solution is washed neutral, dried over sodium sulfate and evaporated. The residue delivers after crystallization from gasoline 3-chloroiminodibenzyl. Yield about 35%.

Claims (3)

Patent claims: 1. Process for the preparation of halogenated iminodibenzyls of the general formula , CH ₂ - H ₂ Cn 40 Example 2 45 A solution of 52.8 parts of 3,7-dichloroiminodibenzyl and 20.2 parts of triethylamine in 500 parts by volume of ethanol is mixed with 5 parts of palladium on charcoal added and hydrogenated at room temperature and normal pressure until the hydrogen uptake ceases (After 3 hours the hydrogen uptake is 97% of theory). After filtering off the Catalyst and evaporation of the filtrate, the residue, as indicated in Example 1, Further worked up, and there are 14 to 16 parts (30 to 35% of theory) of crystallized 3-chloroiminodibenzyl obtain. NH in which X is a chlorine or bromine atom, characterized in that one on compounds of the general formula CH ₂ - H ₂ Cn Hydrogen, optionally under elevated pressure, in the presence of a hydrogenation catalyst and 1 mole of an inorganic or organic base is allowed to act. 2. The method according to claim 1, characterized in that one is in the presence of Raney nickel and an alkali hydroxide is hydrogenated under increased pressure. 3. The method according to claim 1, characterized in that in the presence of a Palladium catalyst and an organic base hydrogenated. Considered publications: Chemischeberichte, Vol. 91 (1958), pp. 1376-1379. 409 687/316 9.64 Bundesdruckerei Berlin