GB581346A - New pyrimidine compounds - Google Patents

Abstract

2 - Arylguanidino - 4 - hydroxypyrimidines wherein either or both of the 5- or 6-positions may be unsubstituted or substituted by a hydrocarbon radicle and wherein the aryl radicle may carry one or more non-acidic substituents such as hydrocarbon radicles (which themselves may bear substituents and which may be attached to the aryl radicle directly or through an oxygen, nitrogen or sulphur atom or a sulphonyl or carbonyl group), halogen atoms or cyano, nitro, acylamino or esterified carboxyl groups, are manufactured by the interaction of an arylbiguanide, whereof the aryl radicle may carry one or more non-acidic substituents, with a formylacetic ester, optionally substituted by a hydrocarbon radicle on either or both of the a - and b -carbon atoms. The reaction may be effected by bringing the reagents together in the presence of a solvent, e.g. ethanol, and, if desired, heating to accelerate the reaction, but not to such high temperatures as to give rise to side-reactions. The arylbiguanide may, if desired, be used in the form of a salt, e.g. the hydrochloride, in which case it is preferable to work in the presence of an acid-binding agent, e.g. sodium ethoxide or caustic soda. In an example, p-bromophenylbiguanide hydrochloride is reacted with ethyl acetoacetate in ethyl alcohol in the presence of aqueous caustic soda solution, to produce 2-p-bromophenylguanidino - 4 - hydroxy - 6 - methyl - pyrimidine. Further examples are given. Specifications 569,099 and 581,334 are referred to. A sample has been furnished under Sect. 2 (5) of 2 - p - dimethylaminophenylguanidino - 4 - hydroxy-6-methylpyrimidine, prepared by the action of ethyl acetoacetate in alcohol in the presence of sodium hydroxide solution on p-dimethylaminophenylbiguanide (obtained by interaction of N : N - dimethyl - p - phenylene - diamine sulphate with dicyandiamide and basification of the reaction mixture). Arylbiguanides are obtainable by heating together in an aqueous medium equimolecular proportions of dicyandiamide and a salt, e.g. the hydrochloride, of the appropriate arylamine, e.g. p-bromoaniline. Formylacetic esters employed in the process of the invention may be prepared by the Claisen reaction between the appropriate esters, or by direct alkylation of the appropriate acylacetic ester.