Ringspaltung cyclischer Azoverbindungen, VI. Photolyse von 8‐Oxo‐8H‐chinazolino[3.2‐c]1.2.3‐benzotriazin Darstellung neuer Diazocine

Products from dehydration of dicarboxylic acids derived from anthranilic acid

“…Treatment of 2,2Ј-iminobis-benzoic acid with hot Ac 2 O has been reported to yield the anhydride 22 (Chart 5). 25 In light of the discoveries reported above, this structural interpretation was questioned, and the 13 C-NMR spectrum of this product revealed three quaternary signals (110.5, 142.7, 159.1 ppm in CDCl 3 ), and a single carbonyl signal (159.8 ppm). The structure must therefore be 23a.…”

Benzazetines and their derivatives (review)

“…More complicated condensed molecules containing the bicyclic fragment of benzotriazine are also capable of eliminating N 2 during irradiation with the formation of compounds containing a benzazetine structure. In particular, the products from photolysis of 8-oxo-8H-quinazolino[3,2-c]-1,2,3-benzotriazine (5) in tetrahydrofuran and dichloromethane are 11-oxo-11H-benz [3,4]azeto [2,1-b]quinazoline (6) (38%) and diphenylamine-2,2′-dicarboximide 7 (yield 47%) [16]. Compound 7 is probably formed from the intermediate 5-oxo-5H-benz [3,4]azeto[1,2-a]quinazoline (8), isomeric with the product 6.…”