Thermal rearrangements of C-(4-Oxo-4H[1]benzopyran-3-yl)-N-phenylnitrone-a route to novel quinolino[2,3-b]chroman-12-ones
作者:M.P.S. Ishar、Kamal Kumar、Rajinder Singh
DOI:10.1016/s0040-4039(98)01362-8
日期:1998.9
-phenylnitrones (1a-c) undergo facile rearrangements on refluxing in benzene, yielding 2-(N-phenylamino)-4-oxo-4H[1]-benzopyran-3-carboxaldehydes (2a-c, 70%) and 3-(phenyliminomethylene)-chroman-2,4-diones (3a-c, 25%). 2a-c undergo cyclization on refluxing with anhydrous AlCl3 in dry CCl4 followed by treatment with sulfuric acid, to give novel quinolino[2,3-b]chroman-12-ones(4a-c) in 90% yield.
C-(4-Oxo-4 H [1]苯并吡喃-3-基)-N-苯基硝酮(1a-c)在苯中回流时容易进行重排,生成2-(N-苯基氨基)-4-oxo-4 H [1]-苯并吡喃-3-羧醛(2a-c,70%)和3-(苯基亚氨基亚甲基)-色氨酸-2,4-二酮(3a-c,25%)。2a-c在无水AlCl 3中在无水CCl 4中回流后进行环化,然后用硫酸处理,以90%的收率得到新型喹啉[2,3 - b ] chroman-12-ones(4a-c)。