Synthesis of some new 4,6-disubstituted-1,2,4-triazin-3,5(2H) diones and related compounds of potential antifungal activity.

The synthesis of 4-substituted amino-6-styryl/alkyl/aryl-1,2,4-triazin- 3,5(2H)diones (4a-d and 15) involving the cyclocondensation of N4-arylaminosemicarbazides(3a-d and 13) with some alpha-ketoacids is described. The behaviour of these triazinones towards amine, hydrazine, isothiocyanate, aromatic aldehyde and gl. acetic acid have been investigated. Structure elucidation of the new compounds has been carried out with the help of elemental analysis, IR, UV and 1H-NMR spectra. The antifungal activity of the prepared compounds has been assayed both in vitro and in vivo against some phytopathogenic fungi associated with wheat grains, were the compound 3b showed a high protection of the grains of wheat against the fungal infection.