Heterocyclic studies. Part XX. The action of hydrazine on some 1,3-dimethyl-lumazines

Abstract

1,3-Dimethyl- and 1,3,7-trimethyl-lumazine [(l; R¹= R²= H) and (l; R¹= Me, R²= H)] were cleaved by hydrazine to give 2-(3-methylaminopyrazine-2-carbonyl)carbonohydrazide (ll; R = H) and its 5′-methyl derivative (ll; R = Me). 1,3,6,7-Tetramethyl-lumazine was cleaved to give 5,6-dimethyl-3-methylaminopyrazine-2-carbohydrazide (X; R¹= Me, R²= H). Reactions of the products with acetone, benzaldehyde, acetic anhydride, nitrous acid, and Raney nickel gave a variety of pyrazine derivatives. ¹H N.m.r. spectra of many of the compounds are recorded.