Patent GB-796996-A (GB)
Title: Imidazole derivatives
IPC: C07D487/04
Filed: 1956-08-02
Abstract: The invention comprises the 1-substituted-2,3,5,6 - tetrahydro - 1 - imidaz - (1,2-a) - imidazoles of the formula <FORM:0796996/IV (b)/1> in which R is an alkyl radical having from 1 to 20 carbon atoms, an aralkyl radical or a dialkylaminoalkyl radical in which the alkyl groups each contain 1-4 carbon atoms, and their acid salts. They may be prepared by refluxing a 1 - (b  - hydroxyethyl) - 2 - substituted - amino-2-imidazoline of formula <FORM:0796996/IV (b)/2> with thionyl chloride and refluxing the 1-(b -chloroethyl) - 2 - substituted - amino - imidazolinium chloride so formed with an alcoholic solution of an alkali metal hydroxide.  In the examples: (a) a solution of thionyl chloride in chloroform is added to 1-(b -hydroxyethyl)-2-(g -dimethylaminopropylamino) - 2 - imidazoline in chloroform solution and the mixture is refluxed, the chloroform and excess thionyl chloride are removed and the residue is dissolved in methanol and treated with potassium hydroxide dissolved in potassium hydroxide to give 1-(g -dimethylaminopropyl) - 2,3,5,6 - tetrahydro - 1 - imidaz(1,2-a) - imidazole; (b) the process of (a) is repeated using 1 - (b  - hydroxyethyl) - 2 - (g -diethylaminopropylamino) - 2 - imidazoline as starting material and methanolic sodium hydroxide in the second stage to give 1-(g  - diethylaminopropyl) - 2,3,5,6 - tetrahydro - 1 - imidaz(1,2-a)-imidazole; (c) thionyl chloride is refluxed with 1 - (b  - hydroxyethyl - 1 - 2 - benzylamino-2-imidazolinium chloride to give 1-(b -chloroethyl) - 2 - benzylamino - 2 - imidazoline which is refluxed with methanolic potassium hydroxide to give 1-benzyl-2,3,5,6-tetrahydro-1-imidaz-(1,2-a) - imidazole; (d) 1 - (b - hydroxyethyl)-2-(b  - dimethylaminoethylamino) - 2 - imidazoline is converted to its hydrochloride salt which is refluxed with alcoholic potassium hydroxide to give 1 - (b  - dimethylaminoethyl) - 2,3,5,6-tetrahydro - 1 - imidaz - (1,2-a) - imidazole; (e) 1-(b  - hydroxyethyl) - 2 - (b  - diethylaminoethylamino) - 2 - imidazoline hydrochloride is refluxed with thionyl chloride to give 1-(b -chloroethyl) - 2 - (b  - diethylaminoethylamino) - 2 - imidazoline hydrochloride which is refluxed with alcoholic potash to give 1-(b -diethylaminoethyl)-2,3,5,6 - tetrahydro - 1 - imidaz - (1,2,-a) - imidazole; (f) 1 - (b  - hydroxyethyl) - 2 - (b  - phenylethyl) - 2 - imidazolinium chloride is refluxed with thionyl chloride and the product is refluxed with alcoholic potash to give 1-(b -phenylethyl)-2,3,5,6 - tetrahydro - 1 - imidaz - (1,2-a) - imidazole; (g) 1 - (b  - hydroxyethyl) - 2 - n - propyl - amino - 2 - imidazolinium chloride is heated by the process of (f) to give 1-n-propyl-2,3,5,6-tetrahydro - 1 - imidaz - (1,2-a) - imidazole; (h) 1 - (b  - hydroxyethyl) - 2 - n - octylamino - 2 - imidazolinium chloride is treated by the process of (f) to give 1-n-octyl-2,3,5,6-tetrahydro-1-imidaz - (1,2-a) - imidazole; (j) 1 - (b  - hydroxyethyl) - 2 - n - dodecylamino - 2 - imidazolinium chloride is treated by the process of (f) to give 1 - n - dodecyl - 2,3,5,6 - tetrahydro - 1 - imidaz - (1,2-a) - imidazole; (k) 1 - (b - hydroxyethyl)-2-n - tetradecylamino - 2 - imidazoline is treated by the process of (f) to give 1-n-tetradecyl-2,3,5,6 - tetrahydro - 1 - imidaz - (1,2-a) - imidazole; (1) 1 - (b  - hydroxyethyl) - 2 - (n - hexadecylamino) - 2 - imidazoline is treated by the process of (f) to give 1-n-hexadecyl-2,3,5,6-tetrahydro - 1 - imidaz - (1,2-a) - imidazole; and (m) 1 - (b  - hydroxyethyl) - 2 - (n - octadecylamino)-2-imidazoline is treated by the process of (f) to give 1 - n - octadecyl - 2,3,5,6 - tetrahydro - 1 - imidaz-(1,2-a)-imidazole.  Specification 796,997 is referred to.