Patent GB-803362-A (GB)
Title: New imidazolium compounds and process for their manufacture
IPC: C07D235/18
Filed: 1955-01-21
Abstract: The invention comprises new imidazolium compounds of formula <FORM:0803362/IV (b)/1> in which the two residues A are the same or different aromatic nuclei which may be substituted and in which two adjacent carbon atoms are linked to the two imidazole nitrogen atoms, R is an alkyl or aralkyl residue which may be substituted, R1 is hydrogen or an alkyl, aryl or aralkyl residue which may be substituted, R3 is a divalent bridge member which contains at least one double bond and which forms with the <FORM:0803362/IV (b)/2> double bonds of the imidazole rings an uninterrupted series of conjugated double bonds, m and n are 1 or 2 and X is an anion. They are prepared by reacting an arylimidazole of formula <FORM:0803362/IV (b)/3> with a compound which is capable of quaternating an imidazole nitrogen atom.  "A" may be, for example, a naphthalene or benzene residue; R1 may be a phenyl residue, an aralkyl residue such as benzyl or menaphthyl, or preferably an alkyl radical having from 1 to 4 carbon atoms, a hydroxy alkyl group such as hydroxyethyl, or a hydrogen atom; R3 may be, for example, <FORM:0803362/IV (b)/4> or <FORM:0803362/IV (b)/5> Suitable quaternating agents are, for example, methyliodide, ethyl bromide, isopropyl chloride, sec.-butyl bromide, dodecyl bromide, epichlorhydrin, dimethyl sulphate, benzyl halides, benzyl halides substituted in the nucleus, for example by halogen, alkyl or alkoxy groups such as p-chlorobenzyl chloride, menaphthyl chloride, aryl sulphonic acid esters, especially those of the benzene series containing alkyl groups having from 1 to 4 carbon atoms and also compounds which contain a water-solubilizing group, such as halogen alkyl- or aralkyl sulphonic acids.  When salts of the imidazoles of the above formula are used as starting materials alkylene oxides, such as ethylene oxide, propylene oxide or glycide, or alcohols having from 1 to 4 carbon atoms, can be used for quaternation.  The quaternation may be carried out by heating the components to 50-200 DEG  C., if desired, under pressure. Inert solvents such as alcohols, dioxane, monomethyl glycol, benzene, toluene, nitrobenzene or mixtures of these may be used. The new compounds may be used as brightening agents.  In the examples: (a) a ,b -di-[N-methyl-benzimidazyl-(2)]-ethylene is treated with p-toluene sulphonic acid ethyl ester to give the compound of formula <FORM:0803362/IV (b)/6> if the N-benzyl substituted compound is used as starting material instead of the N-methyl compound the corresponding benzyl-substituted product is obtained; similarly the methyl ester of p-toluene sulphonic acid may be used instead of the methyl ester; (b) a ,b  - di - [benzimidazyl-(2)]-ethylene is reacted with p-toluene sulphonic acid ethyl ester to give the compound of formula <FORM:0803362/IV (b)/7> a compound of similar properties is obtained when instead of the a ,b -di-(benzimidazyl-(2)]-ethylene 6,61-dimethyl or 6,61-dichloro-a ,b -di - [benzimidazyl - (2)] - ethylene is used; (c) a  - [benzylimidazyl - (2)] - b  - [N - hydroxyethyl-benzimidazyl-(2)]-ethylene is treated with dimethyl sulphate to give the quaternated compound; (d) 1,4-di-[benzimidazyl-(2)]-benzene is quaternated with dimethyl sulphate; (e) a ,b -di-[benzimidazyl-(2)]-ethylene is quaternated with dimethyl sulphate; (f) a ,b -di-[N-methylbenzimidazyl-(2)]-ethylene dihydrochloride is quaternated by treating with methanol; (g) a ,b  - di - [N - methylbenzimidazyl - (2)] - ethylene is quaternated by treating with dimethyl sulphate; (h) a ,b -di-[N-methyl-benzimidazyl-(2)]-ethylene is quaternated by treating with ethyl chloride; (j) 2,5-di-[benzimidazyl-(2)]-furane is quaternated by treating with p-toluene sulphonic acid ethyl ester; (k) an aqueous solution of the compound obtained in (b) is boiled under reflux to give the compound of formula <FORM:0803362/IV (b)/8> (l) potassium iodide is added to the product of (k) to give a compound of formula <FORM:0803362/IV (b)/9> if potassium perchlorate is used instead of the iodide the corresponding perchlorate is obtained; and (m) a ,b -di-[benzimidazyl-(2)]-ethylene disulphonic acid is treated with dimethyl sulphate to give the corresponding quaternated compound. Specification 803,361 is referred to.ALSO:The invention comprises new imidazolium compounds of formula: <FORM:0803362/IV (c)/1> in which the two groups A are the same or different aromatic nuclei which may be substituted and in which two adjacent carbon atoms are linked to the two imidazole nitrogen atoms, R is an alkyl or aralkyl residue which may be substituted, R1 is hydrogen or an alkyl, aryl or aralkyl residue which may be substituted, R3 is a divalent bridge member containing at least one double bond which forms with the >C = N double bonds of the imidazole rings an uninterrupted series of conjugated double bonds, e.g. -CH = CH- , -CH = CH - CH = CH-or <FORM:0803362/IV (c)/2> or m is 1 or 2, and X is an anion.  They may be prepared by reacting the compound <FORM:0803362/IV (c)/3> or a salt thereof with a compound which is capable of quaternating an imidazole nitrogen atom, e.g. alkyl halides, epichlorhydrin, dimethyl sulphate, benzyl halides, benzyl halides substituted in the nucleus, menaphthyl chloride, aryl sulphonic acid esters and halogen alkyl or aralkyl sulphonic acids.  When the salts of the imidazoles are used as starting materials alkylene oxides or alcohols having from one to four carbon atoms may be used as quaternating agents.  In the examples: (a) a ,b -di-[N-methyl-benzimidazyl-(2)]-ethylene is quaternated with p-toluene sulphonic acid ethyl ester to give the compound of formula <FORM:0803362/IV (c)/4> Similar compounds are obtained by substituting a ,b  - di - [N - benzyl - benzimidazyl (2)] - ethylene for the di-N-methyl compound or p-toluene sulphonic acid methyl ester for the ethyl ester; (b) a ,b -di-[benzimidazyl-(2)] ethylene is treated with p-toluene sulphonic acid ethyl ester to give the compound of formula <FORM:0803362/IV (c)/5> Similar compounds can be obtained if instead of a ,b  - di - [benzimidazyl - (2)] ethylene, 6,61 - dimethyl - or 6,61 - dichloro - a ,b  - di [benzimazyl - (2)] ethylene is used; (c) a  - [benzimidazyl - (2)] - b  - [N - hydroxyethylbenzimidazyl-(2)] ethylene is quaternated with dimethyl sulphate; (d) a ,b -di-[N-methyl-benzimidazyl-(2)]-ethylene dihydrochloride is quaternated by treating with methanol; (e) a ,b -di[N-methylbenzimidazyl-(2)] ethylene is quaternated by treating with dimethyl sulphate; (f) a ,b -di-[N-methyl-benzimidazyl-(2)]-ethylene is quaternated by treating with ethyl chloride; (g) the product of which the formula is given in (b) is boiled in aqueous solution under reflux to give <FORM:0803362/IV (c)/6> (h) the product in (g) is treated with potassium iodide to give the compound of formula <FORM:0803362/IV (c)/7> the corresponding perchlorate is obtained if potassium perchlorate is used instead of potassium iodide; and (j) a ,b -di-[benzimidazyl-(2)]-ethylene disulphonic acid is quaternated by treating with dimethyl sulphate.  Specification 803,361 is referred to.