DE1211630B - Process for the preparation of basic fluorene derivatives and their salts - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

C07c

German class: 12 ο-25

Number: 1211630

File number: B 71753 IV b / 12 ο

Filing date: May 4, 1963

Opening day: March 3, 1966

The subject of patent application B 70677 IVb / 12ο is a process for the production of basic fluorene derivatives the general formula

CH - CH ₂ - NH - R ₂

(I)

in which Ri is hydrogen or a low molecular weight alkyl radical and R _{2 is} an alkyl, alkenyl or cycloalkyl group, and its salts, which is characterized in that benzyl compounds of the formula

Process for the production of basic
Fluorene derivatives and their salts

Addition to registration: B 70677IV b / 12 ο interpretation document 1 203 253

Applicant:

C. F. Boehringer & Soehne G. m. B. H.,

Mannheim-Waldhof

Named as inventor:

Dr.-Ing. Kurt Stach, Mannheim

(H) ■ 2 CtiH.5

The process according to the invention is accordingly characterized in that fluorene derivatives are used the formula

in which Ri and R _{2 have} the meaning given above, reacts in a manner known per se with a haloformic acid ester Hal COOR (R = lower alkyl radical) and from the N-carbalkoxy compounds of the formula thus obtained

(IV)

CH - CH - CH ₂
Ri

COOR R>

(III)

in which Ri, R ₂ and R have the meaning given above, the carbalkoxy group is hydrolytically split off in a manner known per se, whereupon the compounds I thus obtained are converted into their salts, if desired.

It has now been found that the above process has a more general and broader application is accessible, the starting products being symmetrical in a particularly advantageous manner N - disubstituted aminoalkylidene fluorene derivatives (IV) can be used, which is much simpler and can be prepared more economically than the N-benzyl compounds of the formula II.

in which Ri and R _{2 have} the meaning given above, with a haloformic acid ester of the formula

Hal - COOR '

in which R 'is a lower alkyl radical, an aryl or aralkyl group, reacts in a manner known per se and the resulting carbalkoxy compounds the formula

COOR '

in which Ri, R ₂ and R 'have the meaning given above, in a manner known per se one

609 510/431

subjected to hydrolytic cleavage, whereupon the obtained N-monosubstituted aminoalkylidene fluorene derivatives (I) if desired converted into their salts.

The reaction of the compounds of the general formula IV with the haloformic acid esters (e.g. Ethyl chloroformate) is carried out by heating in an inert solvent (e.g. xylene). the hydrolytic cleavage of the carbalkoxy group is preferably carried out with aqueous hydrobromic acid effected in glacial acetic acid.

Since the conversion to the N-carbalkoxy compounds V proceeds practically quantitatively, one can the crude products obtained after removal of the volatile components directly from the subsequent hydrolytic process Subjugate division. The preparation of the compounds I can accordingly be very advantageous can also be carried out as a "one-pot process" by combining N-carbalkoxylation and hydrolysis in one Corridor, d. H. without isolating the intermediates V, makes.

The main advantage of the method according to the invention, however, lies in the use of the Technically more accessible starting materials IV instead of the N-benzyl compounds II of the patent application B 70677 IVb / 12o.

The starting compounds IV can be prepared by the process of German Patent 1,150,976 will.

30 example

9- (3-monomethylamino-propylidene) fluorene

A solution of 5.0 g (0.02 mol) of 9- (3-dimethylaminopropylidene) fluorene in 10 ml of xylene is added to a boiling solution of 6.5 g (= 5.7 ml = 0.06 mol) of ethyl chloroformate in 6 ml Add xylene dropwise and heat the contents of the flask to the boil for 1 hour.

The residue obtained after removal of the volatile components in vacuo is crude 9- [3- (N-methyl - N - carbethoxy) - amino - propylidene] - fluorene, which is purified by recrystallization from ligroin can be (m.p. 76 to 77 ° C). The crude product is mixed with 30 ml of glacial acetic acid and 10 ml of 48% strength Hydrobromic acid and refluxed for 3 hours.

The reaction mixture is made alkaline with cooled, dilute lye and extracted with ether. The dried essential extracts are treated with activated charcoal, filtered and precipitated with ethereal Hydrochloric acid. 3.1 g (that is 57.5% of theory) of 9 - (3 - methylamino - propylidene) - fluorene hydrochloride are obtained in this way of m.p. 210 to 212 ° C. By recrystallization from absolute ethanol the increases M.p. at 213-214 ° C.

Claims (1)

Claim: Process for the preparation of basic fluorene derivatives of the general formula CH - CH - CH ₂ - NH - R ₂ Ri in which Ri is hydrogen or a low molecular weight alkyl radical and R _{2 is} an alkyl, alkenyl or cycloalkyl group, and their salts, characterized in that in a modification of the process according to patent application B 70677 IV b / 12 ο fluorene derivatives. the general formula R ₂ CH- CH-CH ₂ -Ν!
Ri (IV) in which Ri and R _{2 have} the meaning given above, with a haloformic acid ester of the formula Shark - COOR ' in which R 'denotes a lower alkyl radical, an aryl or aralkyl radical, in per se brings to reaction in a known manner and the resulting N-carbalkoxy compounds of the formula / COOR ' CH-CH-CH ₂ -Nf (V) I ^X Ro Ri in which Ri, R ₂ and R 'have the meaning given above, subjected to hydrolytic cleavage in a manner known per se, whereupon the N-monosubstituted aminoalkylidene-fluorene compounds thus obtained are converted into their salts, if desired. Considered publications:
Methods of Organic Chemistry, 4th Edition, Vol. XI, Part 1, p. 985. Legacy Patents Considered:
German Patent No. 1 150 976. 609 510/431 2.66 © Bundesdruckerei Berlin