Antitumour pyrimido-triazine antibiotic reumycin prodn. - by dealkylation of an N-alkyl deriv. e.g. xanthothricin by treatment with an amine and subsequent acidification

In a new process for the prodn. of pyrimidotriazine antibiotic reumycin of formula (I) by dealkylation of pyrimidotriazine derivs. of formula (II), dealkylation is carried out with amines, the reaction mixt. is acidified and the end prod. is isolated in a conventional manner. In the formulae R is lower alkyl. Suitable starting material (II) is cpd. in which R is CH3, the known antibiotic xanthothricin. Pref. amines are prim. and sec. amines, esp. those with pKb of 2-6. Dealkylation is generally carried out in a solvent such as an alcohol, ketone or water at alkaline pH (pref. 8-12). Reaction temp. is pref. 10-30 degrees C, usually room temp. (I) has tumour-inhibiting activity, combined with low toxicity. (I) is obtd. in practically quantitative yield. Suivant l'invention le procédé de préparation de reumycine