No abstract

The reaction of 6‐amino‐1,2,4‐triazine‐3,5‐(2H,4H)clione with sodium hydroxide or nitrous acid has been shown to give 5‐hydroxy‐1,2,4‐triazole‐3‐carboxylic acid instead of 6‐hydroxy‐1,2,4‐triazine‐3,5‐(2H,4H)dione as reported in the literature. The triazolecarboxylic acid was also obtained from the aminotriazine and hydrochloric acid.

The ring closure of N,N′‐bis[2‐(dialkoxy)ethyl]‐p‐xylene‐α,α′‐diamine dihydrochloride in fuming sulfuric acid has been investigated and the cyclization products have been identified as the linear pyrido[3,4‐g]isoquinoline as well as the previously reported angular 3,8‐phenanthroline.

Base catalyzed cyclization of ethyl 4‐[2‐(2‐amino‐4,5‐dimethoxyphenyl)ethyl]‐2‐phenylpyrimidine‐5‐carboxylate, derived from ethyl 4‐methyl‐2‐phenyl‐5‐pyrimidinecarboxylate and 3,4‐dimethoxy‐6‐nitrobenz‐aldehyde, gave 5,6‐dihydro‐8,9‐dimethoxy‐3‐phenylbenzo[b]pyrimido[4,5‐f]azocine‐12(11H)‐one, the first reported example of this ring system.