A cyanide-free method for the preparation of 1-(2-pyridyl)isoquinoline-3-carbonitriles (3-cyanoisoquinolines) was developed. The interaction of 5-phenacyl-3-(2-pyridyl)-1,2,4-triazines with 1,2-dehydrobenzene generated in situ from anthranilic acid and an excess of amyl nitrites afforded the target compounds in good yields. The proposed mechanism involves the in situ transformation of the 5-phenacyl group into the 5-cyano group under the action of alkyl nitrite and the following inverse demand aza-Diels–Alder reaction of thus formed 5-cyano-1,2,4-triazines with 1,2-dehydrobenzene affording the target products. The presence of the 5-phenacyl substituent is a key for the reaction, as in case of 5-styryl- or 5-phenylethynyl-3-(2-pyridyl)-1,2,4-triazines the formation of the 1,2,4-triazine ring-transformation products was observed

中文翻译：

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5-苯酰基-1,2,4-三嗪与1,2-脱氢苯在亚硝酸烷基酯存在下反应制备1-(2-吡啶基)异喹啉-3-腈的高效无氰方法

开发了一种用于制备 1-(2-pyridyl)isoquinoline-3-carbonitriles (3-cyanoisoquinolines) 的无氰化物方法。5-phenacyl-3-(2-pyridyl)-1,2,4-triazines 与由邻氨基苯甲酸和过量亚硝酸戊酯原位生成的 1,2-脱氢苯相互作用，以良好的产率得到目标化合物。所提出的机制涉及在亚硝酸烷基酯的作用下 5-苯酰基基团原位转化为 5-氰基基团，以及由此形成的 5-氰基-1,2,4- 的逆向需求 aza-Diels-Alder 反应三嗪与 1,2-脱氢苯反应得到目标产物。5-苯甲酰基取代基的存在是反应的关键，如在 5-苯乙烯基-或 5-苯基乙炔基-3-(2-吡啶基)-1,2,4-三嗪的情况下，1,2观察到,4-三嗪环转化产物