Abstract: 1,3-dioxo-1H-benz(de)isoquinoline-2(3H) butyric acid having the following ructural formula ##STR1## A pharmaceutical composition for treating diabetes mellitus complications comprises an active agent and a pharmaceutical base material, wherein the active agent is a compound selected from the group consisting of 1,3-dioxo-1H-benz(de)isoquinoline-2(3H) butyric acid, and the sodium and potassium salts thereof.

Abstract: 2-(o-carboxyphenylamino)-6H-pyrimido(2,1-b)-quinazolone-6 has the structural formula ##STR1## Derivatives thereof have the structural formulas ##STR2## where A.sup.+ are alkali metals, monoethanolamine, diethylamine. ##STR3## where R is OH, alkyloxyl C 1-4, NHR.sup.1, where R.sup.1 is H, alkyl C 1-4, phenyl, aralkyl. A are salts of inorganic acids ##STR4## where R is alkyloxyl C 1-4, NHR', where R' is alkyl C 1-4. A method of producing 2-(o-carboxyphenylamino)-6H-pyrimido(2,1-b)-quinazolone-6 and derivatives thereof consists in that 2,4-dichloropyrimidine is brought into interaction with anthranilic acid, or a sodium salt of anthranilic acid, or substituted esters, or amides of anthranilic acid in an aqueous medium, or in an organic solvent at a temperature of 90.degree. to 120.degree. C., is kept at this temperature for 1 to 4 hours, and an end product is separated using a conventional method.