DE869342C - Process for the preparation of 5-keto-1, 3, 4, 5-tetrahydrobenz- (cd) -indole - Google Patents

Description

Granted on the basis of the First Oberleiiungsgeseiz of July 8, 194-9

(WiGBl. P. 175)

FEDERAL REPUBLIC OF GERMANY

ISSUED MARCH 5, 1953

GERMAN PATENT OFFICE

PATENT LETTERING

CLASS 12p GROUP 2

H / ppoIVc / * 12 p

Cyril Grob, Basel (Switzerland)

has been named as the inventor

Haco-Gesellschaft A.-G., Gümligen, Bern (Switzerland)

Process for the preparation of 5-keto-1,3,4,5-tetrahydrobenz- (cd) -indole

Patented in the territory of the Federal Republic of Germany on March 29, 1951 Patent application announced on June 26, 1952 Patent granted on January 22, 1953

The priority of applications in Switzerland from April 3, 1950 and March 2, 1951

is used

5-Keto-i, 3, 4, 5-tetrahydrobenz- (cd) -indole is a valuable intermediate product for the production of lysergic acid or those related to lysergic acid Links; it was manufactured using an expensive process (cf. C. UhIe, Journ. At the. Chem. Soc, 71, 761 to 766, 1949)

It has now been found that this ketone is particularly advantageous after a new process can be obtained, which is characterized in that 5 "oxy-benz- (cd) -indoline heated:

0
Ii \ / S /
; : if OH N-CH, N-CH
HH / < γ \ 5-Oxy-benz- (cd) -indoline 5-keto-i, 3. 4> 5 ~ ^te t ^ra ~
hydrobenz- (cd) indole J

The heating of the 5 "oxy-benz- (cd) -indoline for the purpose of rearrangement can be carried out in a simple manner, preferably in the presence of solvents or diluents and catalysts. Suitable solvents ¹ are, for example, benzene, toluene, tetrahydronaphtha-Hn and Decahydronaphthalene: The catalysts that act as hydrogen carriers, such as platinum, palladium, nickel, cobalt and

ίο Nickel chromite, particularly suitable.

This is the starting material for the new process 5 ~ oxy-benz- (cd) -indoline used is up to now not known. It can be done according to the procedure of patent 859166.

The 5-keto-i, 3, 4, 5-tetrahydrobenz- (cd) -indole is said to be an intermediate for the production of Remedies are used.

"". Example ι '

260 parts by weight of 5-oxy-benz- (cd) -indoline are refluxed in a large amount of xylene with 200 parts of 10% palladium-carbon catalyst for 40 to 50 hours. The still hot solution is filtered off from the catalyst, extracted several times with normal hydrochloric acid and washed with water. A crystalline residue contaminated with a little oil is obtained from the xylene solution on evaporation in vacuo, which residue can be purified by chromatography on aluminum oxide or by sublimation in a high vacuum. Esi are 100 · to 120 parts by weight of 5-keto-i, 3, 4, 5 - tetrahy'drobenz - (cd) indole of melting point 162 to 164 ⁰ C obtained.

Pure starting material can easily be recovered from the hydrochloric acid extracts, which is used for a new approach can be used again.

B e i s ρ i e 1 2

2.5 parts by weight of 5 ~ 0 ^x y ~ b ' ^enz ~ (cd) -indoline are stirred in 1600 parts by volume of tetrahydronaphthalene with 3 parts by weight of palladium-carbon catalyst in a nitrogen atmosphere and heated to 190 ° to 195 ° C. for 5 hours. It is then worked up as in Example 1. 1.3 parts by weight of 5-keto-i, 3, 4, 5-tetrahydrobenz- (cd) -indole and 1 part by weight of unchanged starting material are obtained.

Instead of palladium carbon, Raney nickel can also be used be used. When working without a catalyst, the rearrangement is significantly slower in front of you.

In game 3

4 parts by weight of finely powdered 5-oxy-benz- (cd) -indoline are poured into the sleeve of a Soxhlet apparatus. 4 parts by weight of 10% palladium-carbon, 2oo parts by volume of tetrahydronaphthalene and. Brought 100 parts by volume of xylene. The xylene is evaporated by heating in an oil bath at 180-190 ° C, whereby the Ob (d) indoline is gradually extracted. The extraction is complete after about 3 hours. It is refluxed for a further 7 hours. cooks. The solution is filtered hot and freed from unreacted base by extraction with 1η hydrochloric acid. Evaporation of the tetrahydronaphthalene-xylene solution to obtain a residue in vacuo from which upon recrystallization from benzene 5-keto-i, 3, 4, 5-tetrahydrobenz- (cd) indole of melting point 162 to 164 ⁰ C in a yield from 50 to 6o%> is obtained.

Example 4

In a 1000 volume reaction vessel, equipped with a stirrer, gas inlet pipe and an extraction apparatus with a capacity of about 100 parts by volume according to Soxhlet (a water-cooled reflux condenser is connected to the latter), 4 parts by weight of io ° / own palladium-carbon catalyst, 400 parts by volume of tetrahydronaphthalene, 100 parts by volume of xylene and 50 parts by volume of benzene brought. Put 4 parts by weight of pure, fresh into the extraction thimble of the Soxhlet apparatus produced 5-oxy-benz- (cd) -indoline and 80 parts by volume Brought xylene. The reaction vessel is opened with stirring and constant introduction of hydrogen heated for 8 hours in an oil bath from 200 to 20 ° C.

In this way of working, the substance is gradually dissolved out in the Soxhlet apparatus and rearranged in the presence of the catalyst.

The catalyst is removed by filtering the hot mixture. After washing the catalyst with hot xylene, the filtrate is evaporated under reduced pressure at a maximum oil bath temperature of 120 to 130 · ⁰ C '. • Easily pure 5-keto-i, 3, 4, 5-tetrahydrobenz- (cd) -indole can be isolated in excellent yield from the remaining dark crystal mass.

The purification can be carried out as in Example 1 or by recrystallization from benzene-petroleum ether will.

The 5-oxy-benz- (cd) -indoline can also be used in other ways in small proportions gradually in the reaction vessel can be brought, for example with the aid of a feed screw in place of the the aforementioned Soxhlet apparatus.

Instead of the solvent mixture used here pure p-cymene can also be used.

Claims (1)

Claim: Process for the preparation of 5-keto- ¹ J 3> 4j S-tetrahydrobenz- (cd) -indole, characterized in that S-oxy-benz- (cd) -indo-Hn, preferably in the presence of Ver -. diluents or solvents and / or catalysts, optionally with the exclusion of oxygen in the presence of a hydrogen atmosphere, heated. 5746 2.