4‐Amino‐6‐methyl‐3‐(2H)‐thioxo‐5‐(4H)‐oxo‐1,2,4‐triazine (1) was condensed with 2‐methyl (or phenyl)‐4H‐3,1‐benzoxazin‐4‐one (5a,b) in boiling acetic acid to give compounds 8‐11. Reacting 1 with chloroacetyl chloride afforded the corresponding chloroacetamido and triazinothiadiazine derivatives 12 and 13. Condensing 2 with succinic anhydride and/or phthalic anhydride yielded compounds 14 and 15. Benzoylation of 4‐amino‐6‐methyl‐3‐(2H)‐thioxo‐5‐(4H)‐oxo‐2‐(2,3,4,5‐tetra‐O‐acetyl‐α‐D‐glucopyra‐nosyl)‐1,2,4‐triazine (19) afforded the corresponding 4‐N,N‐dibenzoyl derivative 20. Deblocking of the N‐2 glycoside 21 and the S‐glycoside 22 by methanolic ammonia gave compounds 23 and 24. Acetylation of 4‐amino glycoside 25a afforded the corresponding 4‐mono‐ and 4‐diacetyl derivatives 26 and 27. Deamination of 25a,b yielded compounds 28a,b. Methylation of compound 28b afforded the corresponding N4‐ and S‐methyl derivatives 29 and 30.

4-Amino-6-methyl-3-(2H)-thioxo-5-(4H)-oxo-1,2,4-triazine (1) was condensed with 2-methyl (or phenyl)-4H-3,1-benzoxazin-4-one (5a,b) in boiling acetic acid to give compounds 8-11. Reacting 1 with chloroacetyl chloride afforded the corresponding chloroacetamido and triazinothiadiazine derivatives 12 and 13. Condensing 2 with succinic anhydride and/or phthalic anhydride yielded compounds 14 and 15. Benzoylation of 4-amino-6-methyl-3-(2H)-thioxo-5-(4H)-oxo-2-(2,3,4,5-tetra-O-acetyl-α-D-glucopyranosyl)-1,2,4-triazine (19) afforded the corresponding 4-N,N-dibenzoyl derivative 20. Deblocking of the N-2 glycoside 21 and the S-glycoside 22 by methanolic ammonia gave compounds 23 and 24. Acetylation of 4-amino glycoside 25a afforded the corresponding 4-mono-and 4-diacetyl derivatives 26 and 27. Deamination of 25a,b yielded compounds 28a,b. Methylation of compound 28b afforded the corresponding N4-and S-methyl derivatives 29 and 30. J. Heterocyclic Chem., 42, 935 (2005).