GB996706A - Mycobacteriostatic biguanides and compositions containing them - Google Patents

Abstract

The invention comprises an aliphatic-oxyphenyl biguanide of the formula <FORM:0996706/C2/1> or a salt of such a biguanide where either (a) R is an aliphatic group having at least 2 carbon atoms and the aliphatic-oxyphenyl group contains a halogen atom, or (b) no such halogen atom is present and R if an n-alkyl group contains from 5 to 7 carbon atoms and if not an n-alkyl group is a hydrocarbon substituent containing from 5 to 9 carbon atoms, and where in each instance the phenyl nucleus can be further substituted. The aliphatic group may be an alkyl, alkenyl, cycloalkyl or aralkyl group. The phenyl nucleus may contain a halogen atom, a nitro group, an amino group, an aliphatic group or an aryl group. The biguanides may be made by reacting an appropriate aromatic amine with dicyandiamide. The reaction is normally carried out in the presence of acid, e.g. hydrochloric or sulphuric acid, so the initial product is a salt. The reaction may take place in an aqueous medium which can optionally contain a water-miscible solvent, for example a lower alcohol. The temperature is preferably in the range 50-150 DEG C. The free biguanide can be obtained by the action of an alkali, such as sodium or potassium hydroxide. Salts are formed by treating the free biguanide with an inorganic acid, e.g. hydrochloric or sulphuric, or an organic acid such as acetic, oxalic or picric acid, or with an alkyl halide to form a quaternary halide. Examples describe the preparation of 4-n-heptyloxy-; 4-n-amyloxy-; 4-n-hexyloxy; 4-(21-ethylhexoxy)-; 3 - chloro - 4 - n - heptoxy-; 3 - chloro - 4 - n - amyloxy -; 3 - chloro - 4 - ethoxy -; 2,5 - dichloro - 4 - ethoxy -; 2,5 - dibromo - 4 - ethoxy -; and 4 - (21 - chloro-ethoxy)-phenylbiguanides.ALSO:The invention comprises a mycobacteriostatic composition containing as an active ingredient a compound having linked to a nitrogen atom of a biguanide either a halogen-containing aliphatic-oxyphenyl group, the aliphatic-oxy group of which has at least 2 carbon atoms, or an aliphatic-oxyphenyl group in which the aliphatic substituent is a hydrocarbon substituent containing from 5 to 9 carbon atoms, or a salt of such a compound, in admixture with an inert diluent. The composition may be in the form of a suspension or emulsion, preferably aqueous, or a solid. Preferred ingredients are biguanides which have the general formula <FORM:0996706/A5-A6/1> and their salts, where either (a) R is an aliphatic group having at least 2 carbon atoms and the aliphatic-oxyphenyl group contains a halogen atom or (b) no such halogen atom is present and R is a hydrocarbon substituent containing from 5 to 9 carbon atoms, and in either case the phenyl nucleus can be further substituted. The compositions can be used to protect a variety of materials including cloth, leather and agricultural products.