Abstract: Process for the production of methotrexate, which is N[p-([(2,4-diamino-6-pteridyl)-methyl]-N.sup.10 -methylamino)-benzoyl]-L-glutamic acid. The process includes converting 1,1-dichloroacetone with 2,4,5,6-tetraaminopyrimidine in the presence of sodium bisulfite at a constant pH between 3.5 and 5 and at a temperature between 10.degree. and 100.degree. C. The resultant 2,4-diamino-6-methylpteridine is converted in a reaction medium with bromide. 0.3 to 1.0 ml of bromine is used per 1.0 g of the 2,4-diamino-6-methylpteridine. The 2,4-diamino-6-bromo methyl pteridine is converted with p-(N-methyl)-aminobenzoyl-L-glutamic acid or a salt thereof in a polar reaction medium into methoxtrexate.

Abstract: Cationic dyestuffs of the formula ##STR1## wherein A represents oxygen, sulphur or the groupings >N--R.sub.3, ##STR2## wherein R.sub.3 denotes an alkyl, aryl or aralkyl radical,R.sub.4 and R.sub.5 independently of one another denote an alkyl radical,R.sub.6 and R.sub.7 independently of one another denote hydrogen or an alkyl radical,R represents hydrogen or an alkyl group,R.sub.1 and R.sub.2 independently of one another represent hydrogen or an alkyl, aryl or aralkyl radical, orR.sub.1 can be bonded to R.sub.2 or to the ring b, andAn.sup.- represents an anion,and whereinthe rings a and b and the radicals R, R.sub.1, R.sub.2 and R.sub.3 can contain non-ionic substituents which are customary in dyestuff chemistry or carboxyl groups,are suitable for dyeing synthetic and natural materials, in particular paper.