3-thio-4-allyl-6-phenyl-1,2,4-triazine-3,5(2H,4H)-dione; sulfuric acid in formic acid 2 h; Heating;

1: PdCl2(PhCN)2 / tetrahydrofuran / from RT to reflux 2: H2SO4, formic acid / Heating View Scheme

1: 69 percent / sodium methoxide / methanol / Ambient temperature 2: PdCl2(PhCN)2 / tetrahydrofuran / 8 h / Ambient temperature 3: 79 percent / conc. H2SO4, 2-allyl-3-thio-6-phenyl-1,2,4-triazine-3,5(2H,4H)-dione / formic acid / 1 h / Heating View Scheme

2-allyl-3-thio-6-phenyl-1,2,4-triazine-3,5(2H,4H)-dione; sulfuric acid in formic acid 1 h; Heating;

formic acid; sulfuric acid Heating;