Triazines and related products. Part 23. New photo-products from 5-diazoimidazole-4-carboxamide (Diazo-IC)

Abstract

Photolysis of Diazo-IC in dilute aqueous solution affords products which differ according to the pH of the medium. At pH 1, or pH 7.4–12 the product is 2-azahypoxanthine (2): in the intervening pH range the product is 4-carbamoylimidazolium-5-olate (3). In the dark only 2-azahypoxanthine is formed. Photolysis of Diazo-IC in concentrated solution containing citric acid (1 mol equiv.) at pH 2.5 affords a maroon imidazolylazoimidazolium olate (8) and 2-azahypoxanthine.