The Journal of Organic Chemistry

Bridgehead hydrazines. 3. Unusual photorearrangement of 1, 4-diphenylpyridazino [1, 2-b] phthalazine-6, 11-dione

T Sheradsky, R Moshenberg

Index: Sheradsky, Tuvia; Moshenberg, Reuven Journal of Organic Chemistry, 1986 , vol. 51, # 16 p. 3123 - 3125

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Citation Number: 37

Abstract

1, 4-Diphenylpyridazino [1, 2-b] phthalazine-6, ll-dione (% a) was prepared through Diels- Alder reaction of phthalazine and 1, 4-diphenylbutadieneP followed by allylic bromination and thermal 1, 4-dehydrobromination. Upon photolysis, 2a isomerized to an isoindolo [2, 3- a] diazepine derivative, with an oxygen bridge across the seven-membered ring (7). A mechanism which involves an electrocyclic opening and a free radical cycloaddition is ...