Patent GB-798053-A (GB)
Title: Improvements in or relating to iminodibenzyl compounds and processes for their preparation
Filed: 1956-09-27
Abstract: Substituted iminodibenzyl compounds of the general formula <FORM:0798053/IV (b)/1> wherein A represents the trivalent hydrocarbon group <FORM:0798053/IV (b)/2> , the various nitrogen groups being attached to any of the three free valencies thereof and the groups R are the same or different and represent, when taken separately, a hydrogen atom or an alkyl group containing not more than 4 carbon atoms and when taken with the nitrogen atom as the group -N(R)2 represent a residue of a saturated heterocyclic amine, and the corresponding compounds in which one or both of the benzene nuclei of the iminodibenzyl contain alkyl groups containing not more than 4 carbon atoms, and acid addition salts and quaternary ammonium derivatives thereof, and the preparation thereof by any of the following methods: (a) by alkylating a corresponding compound in which at least one of the R groups is replaced by a hydrogen atom; (b) by condensing a diamine of the formula <FORM:0798053/IV (b)/3> or a salt thereof, with the required iminodibenzyl, Hal representing a halogen and R having the above significance; (c) by condensing an amine of the formula NH(R)2 with an iminodibenzyl compound of the general formula <FORM:0798053/IV (b)/4> wherein Z represents an acid residue of a reactive ester such as a halogen atom or a sulphuric or sulphonic ester residue, and the other represents either a said residue of a reactive ester or an -N(R)2 group, and the other symbols have the above significance-preferably under pressure, particularly when a volatile amine is used; (d) by heating to effect decarboxylation a compound of the general formula <FORM:0798053/IV (b)/5> all symbols have the above significance; (e) by reducing with lithium aluminium hydride a compound of one of the general formul <FORM:0798053/IV (b)/6> and <FORM:0798053/IV (b)/7> wherein R1 represents hydrogen or an alkyl group containing not more than 3 carbon atoms, and the other symbols have the above significance; (f) by catalytically hydrogenating in the presence of a compound of the formula HN(R)2 an iminodibenzyl compound of the general formula <FORM:0798053/IV (b)/8> or <FORM:0798053/IV (b)/9> in the presence of a compound of the formula HN(R)2, wherein A1 represents a -CH-CH2-grouping, T represents a -CHO or -CN group and R has the above significance or wherein T represents a -CN group, without the concomitant presence of a coumpound of the formula HN(R)2; (g) by cyclizing a compound of the general formula <FORM:0798053/IV (b)/10> wherein Hal represents a halogen atom and the other symbols have the above significance, in the presence of a substituted amide of a lower aliphatic acid such as formamide or acetamide, and a condensing agent, e.g. an alkali metal hydroxide or carbonate, and optionally in the presence of copper powder.  When method (b) above is used, some isomerization may take place to form an iminodibenzyl compound of the general formula <FORM:0798053/IV (b)/110> wherein all symbols have the above significance, and the isomer may be separated by crystallisation of a salt such as the dihydrochloride in alcohol, or by chromatography.  Acid addition salts which may be prepared are the hydrochlorides, hydrobromides, citrates, tartrates and 8-chloro-theophyllinates, and the quaternary ammonium compounds which may be prepared are the quaternary ammonium iodides and bromides.  In the examples 5-(2,3-bis-dimethylamino-1-propyl)-iminodibenzyl and the hydrochloride and iodomethylate thereof, 5-(2,3-bis-diethylamino-1-propyl) iminodibenzyl, and 5-(1,3-bis-dimethylamino-2-propyl) iminodibenzyl and the corresponding 1,3-bis-diethylamino compound are prepared.  Starting compound.  1,3 - Bis - dimethylamino - 2 - propyl iminodibenzyl - 5 - carboxylate is prepared by condensing 1,3-bis-dimethylamino - 2 - propanol with iminodibenzyl - 5 - carboxylic acid chloride (obtainable by the action of phosgene on iminodibenzyl.