of formula hnr 4 r 5 in which r 4 and r 5 are as defined above preferably this reaction is performed in a suitable inert solvent for example tetrahydrofuran at the boiling point of the reaction mixture for a period of eight to 24 hours if desired the compounds of formula 1 in which both r 4 and r 5 are hydrogen may be further n alkylated on the nitrogen of the primary amine with the appropriate lower alkyl halide to the corresponding compounds of formula 1 in which r 4 is hydrogen or lower alkyl and r 5 is lower alkyl i e secondary or tertiary amines in this case depending on the particular derivative desired the n alkylation may be effected with one or two moles of the alkyl halide to give respectively the secondary r 4 h and r 5 lower alkyl or tertiary amine r 4 r 5 lower alkyl on the other hand the n alkylation may be effected in two steps introducing a different alkyl group each time to afford the corresponding tertiary amine in which r 4 and r 5 are different lower alkyls when it is desired to prepare the above tertiary amine compounds in which r 4 or r 5 are either or both methyl an alternative alkylation method comprises reacting the appropriate corresponding primary or secondary amine with an aqueous mixture of a substantial excess of formaldehyde and formic acid according to the conditions of the eschweiler clarke reaction see m l moore organic reactions 5 301 1949 whereby n methylation is effected d preparation and conversion of intermediates of formula 3.