1960 年 80 巻 1 号 p. 21-24
Synthesis of dl-isolaureline (1, 2-methylenedioxy-9-methoxyaporphine) (I) by Pschorr's cyclization reaction has already been carried out independently by Marion and Faltis, but no report has been made regarding side reaction in this procedure. This point was followed in the present series of experiments and reëxamination was made on Pschorr's phenanthrene cyclization reaction of the amine (VIII). The synthesis was carried out in accordance with the procedure described in the past literature and shown in Chart 1, and the result same as that described was obtained. However, this cyclization reaction of the amine (VIII), besides giving the main product of aporphine (I) in approximately the same yield as that obtained by past workers, was accompanied by the formation of a small amount of two kinds of substances, hydrohydrastinine (IX) and 5-methoxyindiazole (X), whose formation was not mentioned in the said literature. It was thereby confirmed that this cyclization reaction is also accompanied by a side reaction by which a part of the reactant was severed into two upper and lower fragments, exactly the same as in the Pschorr reaction during synthesis of 1, 2, 9-trimethoxyaporphine (II) experienced by the present authors.