Phthalazine誘導体に関する研究(第11報)1-置換および1,4-ジ置換Phthalazine N-OxideとAcetic AnhydrideおよびAcid Chlorideとの反応

抄録

Reaction of 1-phenylphthalazine 3-oxide (I) and acetic anhydride afforded a ringexchange product, 2-(2-acetoxy-2-phenyl-1, 2-dihydrobenzocyclobuten-1-yl)-4-phenyl-1 (2H)-phthalazinone (V) and 9, 10-anthraquinone (VII), indicating cleavage of the pyridazine portion in I. Examinations were then made on the reaction of I, 1, 4-diphenylphthalazine 2-oxide (XIII), 1-benzyl-4-phenylphthalazine 2-oxide (XVI) and 3-oxide (XVII), and 1-ethyl-4-phenylphthalazine 2-oxide (XVIII) with acid chlorides. The reaction of I and benzoyl chloride gave the ring-exchanged product (VII), V-X (V in which acetoxyl is replaced with benzoyloxyl), 2-(2-benzoylbenzyl)-4-phenyl-1 (2H)-phthalazinone (V'), and 3-phenyl-1, 3-dihydro-1-isobenzofuranol (IX) ; that of I and acetyl chloride gave 3-phenylphthalide (XI) ; that of XIII and benzoyl chloride gave 1, 3-diphenylisobenzofuran (XIV) and o-dibenzoylbenzene (XV) ; and that of XIII with acetyl chloride and methanesulfonyl chloride respectively afforded XIV and XV. It was considered that these products were formed via a four-membered intermediated produced by the liberation of nitrogen.