STUDIES ON SOME 6-SUBSTITUTED 1,2,4-TRIAZINES AND THEIR THIO-ANALOGUES

Abstract

When 4-amino-6-methyl-5-oxa-3-thio[1,2,4]triazine (1) was allowed to react with phosphorus pentasulphide in boiling dioxane 4-amino 3,5-dithio-6-methyl-[1,2,4]triazine (2) was obtained.

Condensation of 1 with (2-thiophene-and/or pyridine-)aldehyde (3a,b) in refluxing methanol with one drop of glacial acetic acid gave 6-methyl-lf-((thien­ and/or pyrid-)2-yl-methylene)-amino-3-thio-4H[1,2,4]triazin-5-one (4a,b), respectiv­ ely.

0

1 YN-N=cHR

N,N S

4; a, R=2-thienyl b, R=2-pyridyl

Stirring 4a,b with benzyl chloride in methanol in the presence of potassium hydroxide at r.t. gave 3-Benzyl sulphanyl-6-methyl-4[((thien-and/or pyrid-)2-yl methylene)-amino]-4H-[1,2,4]triazin-5-one (Sa,b) respectively. 0

Jj.CYN-N=cHR

N,NASCH2 Ph -

5 a,R=2-thienyl b,R=2-pyridyl

Refluxing Sa,b with hydrazine hydrate in methanol afforded 3-hydrazino-6- methyl-4[((thien-and/or pyrid- )2-yl methylene)amino]-4-[1,2,4]triazin-5-one (6a,b)