GB747668A - Improvements in or relating to process for the preparation of guanidino substituted fatty acids - Google Patents

Abstract

Alpha guanidino-substituted fatty acids are prepared by admixing a guanidine salt, alkali metal hydroxide and an alpha halo fatty acid in an aqueous medium of not more than about 15 mols. of water per mol. of guanidine salt, allowing the reaction to proceed to completion, and separating alpha guanidino-substituted fatty acid from the reaction products. Any alpha halo fatty acid may be used, for example chloracetic acid, alpha-chloropropionic acid and alpha bromoacetic acid. The preferred guanidine salt is the hydrochloride, but the nitrate or sulphate may also be used. Sodium and potassium hydroxides are preferred and may be added as a powder, as pellets or as a solution. In examples: (1) one mol. of guanidine hydrochloride is admixed with one mol. of sodium hydroxide with stirring and one mol. of 50 per cent aqueous sodium hydroxide and one mol. of chloracetic acid are added over four hours at a temperature of 35-40 DEG C.; the mixture is allowed to stand at 35 DEG C. for 24 hours then diluted in water, agitated at 70-80 DEG C. for one hour and then cooled, whereupon glycocyamine is separated by filtration; (2) crude guanidine hydrochloride is prepared by heating ammonium chloride and dicyandiamide and treated as in (1). According to other embodiments, all of the alkali metal hydroxide is admixed with the guanidine salt and the halo fatty acid is added portionwise thereto, or the halo fatty acid and all the alkali metal hydroxide are first admixed and then added portionwise to the guanidine salt, or the guanidine salt, halo fatty acid and half of the alkali metal salt are admixed initially and the rest of the alkali hydroxide is added portionwise to the resulting mixture. In general, the portionwise additions are made at a temperature between 0 DEG and 60 DEG , preferably 30-40 DEG C., with agitation over a period of 2 to 24 hours, preferably 4-8 hours, and then the mixture is allowed to stand for 8 to 30 hours at the same temperature to complete the reaction. Specification 6486/40 (as open to inspection under Sect. 91), is referred to.