Streptonigrin関連化合物の合成研究(第8報) : Ethyl 3-cyano-4-(3,4-dimethoxyphenyl)-6-methyl-2-quinolyl-5-pyridinecarboxylateの加水分解とHofmann反応について 複素環式化合物の合成研究 第199報

抄録

Attempts to convert the substituents in the pyridine ring of the compound (III), which was synthesized according to the procedure described in a preceding paper, into the same groups as the substituents in the pyridine ring (C) of strptonigrin (I) and its derivative (II) were investigated, and the cyano group of III (R=3, 4-dimethoxyphenyl-) could be converted into amino group successfully, but conversion of nitrile to the other groups resulted in failure. In this case, the cyano group extremely resisted to the hydrolysis to give an unusual abnormal product (XIX) under certain conditions or an unexpected compound (XVIII) through a removal of the cyano group. Furthermore, reduction of III with lithium aluminum hydride afforded the compound (XII) through a removal of the nitrile, unexpectedly. In the case of Hofmann reaction of the amide (XVII), the compound (XXI) expected was found to be formed together with an abnormal product (XXII), and catalytic hydrogenation of phenylurethan (XXVIII) of the alcohol (XXVI), which was obtained by reduction of the above compound (XXI), resulted in failure.