Trioxopteridine derivatives of the formula ##STR1## , wherein R.sub.1 is a normal alkyl group having 0 to 6 hydroxyl groups and R.sub.2 is hydrogen or a normal lower alkyl group having 0 to 5 hydroxyl groups, are prepared by catalytically hydrogenating a 6-substituted-5-nitro-2,4-dioxopyrimidine to give a 6-substituted-5-amino-2,4-dioxopyrimidine, and then reacting the latter compound with a compound of the formula R.sub.2 --A--COOR.sub.3, wherein R.sub.3 is hydrogen, lower alkyl, an alkali metal or an alkaline earth metal and A is carbonyl or a group of the formula ##STR2## wherein R.sub.4 is lower alkyl. The resulting trioxopteridine derivatives have analgesic and antiphlogistic properties and are therefore useful as pharmaceutical medicaments.
