4,6-DIMETHOXY-3-METHYL-1,3,5-TRIAZIN-2(3H)-ONE AND 6-METHOXY-3,5-DIMETHYL-1,3,5-TRIAZINE-2,4(3H,5H)-DIONE

2,4,6-Trimethoxy-1,3,5-triazine, (I), undergoes methyl transfer in a few stages to 1,3,5-trimethyl-2,4,6-trioxohexahydro-s-triazine, (IV). The crystal structures of the two intermediates, 4,6-dimethoxy-3-methyl-1,3,5-triazin-2(3H)-one, (II) (C6H9N3O3), and 6-methoxy-3,5-dimethyl-1,3,5-triazine-2,4(3H,5H)-dione, (III) (C6H9N3O3), are described. Molecules of (II) form a layer structure made up of infinite ribbons. Molecules of (III) related by an inversion centre are arranged in pairs.