Studies on diazepines. XXI. Photochemical synthesis of 1H-2,4-benzodiazepines from 4-azidoisoquinolines.
作者:HIROYUKI SAWANISHI、HARUKI SASHIDA、TAKASHI TSUCHIYA
DOI:10.1248/cpb.33.4564
日期:——
Irradiation of 4-azidoisoquinolines (1a-e) in the presence of sodium methoxide resulted in ring-expansion to give 5-methoxy-1H-2, 4-benzodiazepines (10) : the structures of the products were confirmed by the following chemical studies as well as spectral analyses. Treatment of the diazepines (10) with hydrochloric acid or acidic alumina in methanol resulted in ring-contraction to afford 1-aminoisoindolenines (14), and treatment with acetic anhydride gave the ring-opened products (16). The diazepines (10) were also converted to 1-methoxyisoindolenines (19) by further irradiation and to the diazepin-3-one (21) by treatment with either mesitylnitrile oxide or lead tetraacetate.
在甲醇钠存在下辐照 4-叠氮异喹啉(1a-e)会导致环扩张,生成 5-甲氧基-1H-2, 4-苯并二氮杂卓(10):产品的结构通过以下化学研究和光谱分析得到证实。用盐酸或甲醇中的酸性氧化铝处理二氮杂卓(10)会导致缩环,得到 1-氨基异吲哚烯类(14),用乙酸酐处理会得到开环产物(16)。通过进一步辐照,二氮杂环庚烷(10)还可转化为 1-甲氧基异吲哚烯类(19),而通过氧化间甲苯胺或四乙酸铅处理,则可转化为二氮杂环庚烷-3-酮(21)。