Different modes of alkaline hydrolysis of fervenulin and isofervenulin

Unlike rheumycin and fervenulin, isofervenulin and 3-methylisofervenulin are hydrolyzed by aqueous alkalies at the N₍₅₎-C₍₆₎ bond. On acidification of the reaction mixture, the N-carboxy-N-methylcarbamoyltriazines formed are reconverted into the starting isofervenulins, and on basification (pH>10) into methylaminotriazinecarboxamides. A by-product of the alkaline hydrolysis of isofervenulin is a product of the contraction of the uracil ring, namely imidazotriazinone-7a-carboxylic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1555–1559, November, 1987.