3,336,308 United States Patent Office Patented Aug. 15, 1967 1. 2 3,336,308 at room temperature. Two mols or a small excess there NOVEL AMNO HALO-BENZYLAMINES over of the halogenation agent, such as chlorine or bro Johannes Keck, Biberach (Riss), Germany, assignor to mine, are used per mol of amino benzylamine. The Boehringer Ingelheim G.m.b.H., Ingelheim am Rhine, hydrochloric or hydrobromic acid salts initially formed Germany, a corporation of Germany thereby may either be isolated directly and may be purified No Drawing. Filed June 4, 1965, Ser. No. 461,492 by recrystallization, or the compounds may be purified Claims priority, application Germany, Oct. 14, 1963, in known fashion by way of their free bases and may then T 24,890; Apr. 9, 1965, T 28,358 be transformed into any other desired acid addition salt. 10 Claims. (C. 260-247.5) Method B-Reaction of a (3,5-dihalo-diacylamino This application is a continuation-in-part application 10 benzyl) halide of the formula of my copending applications Ser. No. 237,714 filed Nov. 14, 1962 and Ser. No. 403,339, filed Oct. 12, 1964, now abandoned. X >- CH-Hal The invention relates to novel amino-halo-benzylamines 5 (Ac).2N having a formula selected from the group consisting of X wherein X has the above definition, Hal is a halogen and NH R Ac is any desired acyl radical with an amine of the formula 20 N R R1 H-NC and - R1 25. wherein R and R1 have the above definition and subse quently splitting off the acyl radicals. This reaction is performed in the presence of an agent II which ties up or neutralizes the hydrogen halide split off 30 by the reaction. An inorganic or tertiary organic base or wherein G is a halogen selected from the group consisting also an excess of the amine of Formula IV may be used of chlorine and bromine, R is selected from the group for this purpose, an excess of at least one mol of amine consisting of hydrogen, lower alkyl, hydroxy lower alkyl, being used per mol of (3,5-dihalo-diacylamino-benzyl)- halo lower alkyl, lower alkenyl, cyclo alkyl, aralkyl and halide. The reaction is advantageously performed in the aryl, R1 and R2 are selected from the group consisting of 35 presence of an inert organic solvent, such as ethanol, ben lower alkyl, lower alkenyl, cycloalkyl, aralkyl, hydroxy Zene, toluene, etc., and at elevated temperatures, preferably lower alkyl, halo lower alkyl, pyridyllower alkyl, and aryl, at the boiling point of the particular solvent employed. In and R and R1, and R1 and R2 when taken together with the event that an excess of the amine IV or a tertiary the nitrogen atom form a heterocyclic selected from the organic base is employed as the agent to tie up the group consisting of pyrrolidino, lower alkyl pyrrollidino, 40 hydrogen halide split off by the reaction, these agents may piperidino, lower alkyl piperidino, piperazino, lower alkyl simultaneously serve as the solvent for the reactants. piperazino, hexamethylene imino, lower alkyl hexamethyl The deacylation is effected according to known method, ene imino, and Ri and R2 together with the nitrogen atom preferably by heating the acylated compound with a dilute also form a heterocyclic selected from the group consist mineral acid or a dilute inorganic base. ing of lower alkyl morpholino and morpholino, and R3 45 Method C.-Reduction of (halo-nitro-benzyl) amine and R4 are different and are selected from the group of the formula consisting of hydrogen and -NH2 and their non-toxic, pharmacologically acceptable acid addition salts. Lower alkyl means alkyl having 1 to 7 carbon atoms. The inven- . NO2 i R tion also relates to novel compositions and method of 50 -CBI-N increasing secretion of the trachea-bronchial, an of y R1 Suppressing coughs. The compounds of the invention may be prepared by and methods which are well known in principle for the synthe X sis of other halogenated-amino-benzylamines. The follow 55 Ri ing processes have been found to be especially advan ? -CH-N- tageous but the compounds may also be prepared by other known analogous methods. No, YT- Ra Method A.-Chlorination or bromination of amino 60 wherein R, R1, R2 and X have the above definitions. benzylamines of the formula The reaction is performed according to known meth ods, preferably by catalytic reduction, for instance, with hydrogen in the presence of precious metal catalysts, Such as platinum or palladium, advantageously in a 65 solvent, such as methanol, ethanol, tetrahydrofuran or dioxan; or by reduction with hydrazine hydrate Raney nickel, preferably in a solvent such as methanol; or by reduction with nascent hydrogen which is formed from wherein R1,R2 R3 and R4 have the above definitions. iron, zinc or tin and a mineral acid, for example. How The reaction is performed in the presence of an inert 70 ever, the reduction may also be performed by any other organic solvent, preferably in the presence of a halogenated known process for transformation of aromatic nitro hydrocarbon or glacial acetic acid, and advantageously compounds into aromatic amino compounds. 3,336,308 e 4. ed tion had been added, the chloroform phase was shaken Method D.-By reduction of an amino-halo-benzamide with 100 cc. of 2 N sodium hydroxide. The chloroform of the formula phase was then separated, dried over sodium sulfate and evaporated. The oily residue was identified to be N-(2-amino-3,5-dibromobenzyl)-diethylamine of the for R1 mula N NE N Ra C2Es X Br CH-N and 10 X C2H5 R. R3- - -N br R This compound was dissolved in 50 cc. of ethanol, and R4 5 then hydrogen chloride was introduced into the Solu tion, whereby the hydrochloride of the free base was ob wherein R, R, R2, R, R and X have the above defini tained. The hydrochloride had a melting point of 214 tions. 214.5 C. The best yields are obtained by reducing the said 20 EXAMPLE 2 benzamides with a complex metal halide, preferably Preparation of N-(4-amino-3,5-dibromobenzyl) - diethyl lithium aluminum hydride. The reduction is carried out amine hydrobromide in an inert anhydrous organic solvent, preferably abso lute ether, and at moderately elevated temperatures, A solution of 39.5 gm. of bromine in 150 cc. of glacial most advantageously at the boiling point of the solvent. 25 acetic acid was slowly added dropwise to a solution of The reduced product can be isolated from the reaction 12.6 gm. of N-(4-aminobenzyl)-diethylamine in 150 cc. mixture in customary fashion. of glacial acetic acid, accompanied by stirring. The glacial The starting materials for the above methods are known acetic acid was decanted from the precipitate, and the from the literature or may be prepared by methods de precipitate was recrystallized from ethanol. It was identi Scribed in the literature. For example, the diacylamino 30 fied to be N-(4-amino-3,5-dibromo-benzyl)-diethylamine halo-benzyl halides may be prepared by reacting 2-diacyl hydrobromide of the formula amino-halotoluene with N-bromosuccinimide or with halogen under ultraviolet light. The nitro-halo-benzyl C.H. amines may be prepared by reacting a nitro-halo-benzyl BT CH-N HBr halide with an appropriate amine. The amino-halo-benz C2H5 amides may be prepared by a halo-nitrobenzoyl halide HN with a secondary amine and reducing the nitro group of the intermediate to an amino group. Br The free bases of the invention may be transformed having a melting point of 218 C. (decomposition). by known methods into their non-toxic, pharmacological 40 ly acceptable acid addition salts, for instance, by react EXAMPLE 3 ing an alcoholic solution of the particular acid with the Preparation of N-(2-amino-3,5-dibromobenzyl)-disobu free base. Examples of suitable acids are inorganic acids tylamine hydrobromide Such as hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid and organic acids such as lactic A solution of 8.5 gm. of bromine in 30 cc. of glacial acid, citric acid, tartaric acid, maleic acid, 8-chloro 45 acetic acid was added dropwise to a solution of 6.09 gm. theophylline, etc. The said addition salts are water of 2-aminobenzyl-diisobutylamine in 150 cc. of glacial soluble. acetic acid, accompanied by stirring. The glacial acetic The novel compounds of the invention possess useful acid was decanted from the precipitate formed thereby, pharmacodynamic properties in warm-blooded animals. and the precipitate was recrystallized from ethyl acetate. More particularly, they exhibit an excellent secretolytic It was identified to be N-(2-amino-3,5-dibromobenzyl)- activity (increase bronchial secretions) with extremely diisobutylamine hydrobromide of the formula low toxicity and cough-Suppressing, monoaminooxidase NE iso-C4H9 inhibiting and antipyretic activities. / The dosage unit of the compound of the invention is Br CH-N HBr from 1 to 100 mg. depending upon the desired activity. Thus, the effective individual dose for increasing bron iso-C4H9 chial Secretion is from 0.5 to 10 mg., preferably 2 to 4.0 mg, while the effective antitussive dose is 10 to 100 mg., Br preferably 25 to 50 mg. The compounds can be ad ministered perorally or parenterally in the form of tablets, 60 having a melting point of 165-167 C. coated pills, syrups, aerosols, solutions, suspensions, Sup EXAMPLE 4 positories, etc. Preparation of N-(2-amino-3,5-dibromobenzyl) - dialyl In the following examples there are described several amine hydrochloride preferred embodiments to illustrate the invention. How 65 ever, it should be understood that the invention is not A mixture of 24.7 gm.