GB757650A - Improvements in or relating to substituted imidazolines and the preparation thereof - Google Patents

Abstract

The invention comprises substituted imidazolones of the general formula <FORM:0757650/IV(a)/1> wherein n is 2 or 3, and their acid addition and quaternary salts, and the preparation thereof by condensing a carboxylic acid of the general formula <FORM:0757650/IV(a)/2> wherein n has the above significance or a lower alkyl ester or nitrile thereof, with ethylenediamine or an acid addition salt thereof. Suitable esters are the methyl, ethyl, propyl, isopropyl, butyl, pentyl and hexyl esters. The reaction is preferably carried out by heating, e.g. the nitrile may be heated with the p-toluenesulphonic acid salt of ethylene diamine. The acid addition salts are prepared by contacting the free imidazolines with an acid to form, for example, the tartrate, citrate, phthalate, lactate, formate, phosphate, nitrate, sulphate, hydrochloride, hydrobromide, hydroiodide and acetate salts, and the quaternary salts are formed by reaction with an ester, e.g. an alkyl halide or sulphate such as dimethylsulphate, methyl iodide, ethyl bromide and propyl chloride. In the examples, 2-(1,2,3,4-tetrahydro - 1 - naphthyl) - imidazoline and its hydrochloride, dehydrogen phosphate, hydrobromide, cyclohexylsulphamate, bitartrate and saccharinate salts and the hydrochloride salt of 2-(1-indanyl)-imidazoline are prepared. Intermediate compounds. 1,2,3,4-Tetrahydro-1-naphthonitrile is prepared by heating the corresponding 1-naphthoamide with thionyl chloride. Lower alkyl esters of 1,2,3,4-tetrahydro-1-naphthoic acid and 1-indone-carboxylic acid are prepared by heating the free acids with alcohols, e.g. methyl alcohol.