GB599713A - Manufacture of alkyl-substituted dicyandiamides - Google Patents

Abstract

Alkyl-substituted dicyandiamides of the general formula R-NH-C( : NR1)-NH-CN, wherein R represents an alkyl (or cycloalkyl) group and R1 hydrogen or an alkyl (or cycloalkyl) group, are manufactured by the interaction of N-alkyl-N1-cyano-S-alkylisothioureas, of the general formula R.N = C(SR11)-NH-CN (wherein R11 represents a lower alkyl group), with ammonia or a primary aliphatic amine. In examples: (1) N-methyl-N1-cyano-S-methylisothiourea is heated in a closed vessel with a saturated solution of ammonia in ethanol to produce o -methyldicyandiamide; the product may be coverted into its salts with picric and flavianic acids by mixing alcoholic solutions of the acids and the base; (2) N - ethyl - N1 - cyano - S - methylisothiourea similarly yields o -ethyldicyandiamide and its picric and flavianic acid salts; (3) N-isopropyl-N1-cyano-S-methylisothiourea similarly yields o -isopropyldicyandiamide; (4) N-n-propyl-N1-cyano-S-methylisothiourea similarly yields o -n-propyldicyandiamide; (5) N-n-butyl-N1-cyano-S-methylisothiourea similarly yields o -n-butyldicyandiamide; (6) N-isobutyl-N1-cyano-S-methylisothiourea similarly yields o -isobutyldicyandiamide; (7) the alcoholic ammonia in (1) is replaced by aqueous methylamine solution, producing o : o 1-dimethyldicyandiamide; (8) aqueous ethylamine solution similarly yields o - methyl - o 1 - ethyldicyandiamide; (9) n-butylamine (in ethanol) similarly yields o -methyl - o 1 - n - butyldicyandiamide; (10) N-isopropyl - N1 - cyano - S - methylisothiourea is heated in a closed vessel with n-propylamine to give o - n - propyl - o 1 - isopropyldicyandiamide; (11) N - ethyl - N1 - cyano - S - methylisothiourea and isopropylamine similarly yield N2 - ethyl - N3 - isopropyldicyandiamide; (12) N - isopropyl - N1 - cyano - S - methylisothiourea and aqueous ethylamine solution yield the same product; (13) N - isopropyl - N1 - cyano - S - methylisothiourea and isopropylamine similarly yield N2 : N3-di-isopropyldicyandiamide; (14) n-butylamine similarly yields N2 - isopropyl - N3 - n - butyldicyandiamide; (15) cyclohexylamine similarly yields N2 - isopropyl - N3 - - cyclohexyldicyandiamide. Specification 599,714 is referred to. N-Alkyl-N1-cyano-S-alkylisothioureas are obtainable by the interaction of the appropriate alkyl isothioeyanate (e.g. methyl, ethyl, n- or iso-propyl or n- or iso-butyl isothiocyanate) with sodium cyanamide in alcohol, and alkylation of the resulting N-alkyl-N1-cyanoisothiourea sodium salt, e.g. with methyl iodide.