Rearrangement of 1,2,4-triazin-3-ones to imidazolin-2-ones and of cinnolin-3-one to oxindole
Abstract
Amination of cinnolin-3-one with hydroxylamine-O-sulphonic acid gives 2-aminocinnolin-3-one which undergoes a novel rearrangement to oxindole; similar treatment of 1,2,4-triazine-3-ones gives high yields of the analogous ring-contracted products, imidazolin-2-ones, directly.