SYNTHESIS IN THE ALLOXAZINE. ISOALLOXAZINE (FLAVIN)AND LUMAZINE GROUPS. PART III. SYNTHESIS OF SOME ACID DERIVATIVES.

The synthesis of some acids of the alloxazine and  flavine groups has been nuder taken for some chemotherapeutic purposes. \(o\)-Phenylenediamine-4-sulphonic acid and 1:2-diaminonaphthalene-4-sulphonic acid yield with alloxan the corresponding alloxazine derivatives. Flavin-9-propionic acid has been synthesised starting from \(o\)-nitroaniline by the method of Kuhn, but attempts to synthesise the corresponding 6-methyl derivative did not meet with success, a product, m.p-  225°, being obtained instead. 3 =4 Diaminocinnamic acid yields with alloxan the corresponding alloxazine-acrylic acid.