Syntheses of 2<i>H</i>-1-Benzothiopyran-2-ones (Thiocoumarins) and Related Compounds from Benzenethiols and Diketene
作者:Hiroyuki Nakazumi、Akira Asada、Teijiro Kitao
DOI:10.1246/bcsj.53.2046
日期:1980.7
The products formed by the reaction of benzenethiols with diketene in the presence of H2SO4 are (E)-β-(arylthio)crotonic acids (2) and/or isomeric (Z)-β-(arylthio)crotonic acids and not, as has been reported, S-phenyl 3-oxobutanethioates (1). Compounds 1a–k, as the precursor of thiocoumarins, were prepared from benzenethiols and diketene in the presence of triethylamine. The reaction of 1 with various
苯硫醇与双烯酮在 H2SO4 存在下反应形成的产物是 (E)-β-(芳硫基)巴豆酸 (2) 和/或异构 (Z)-β-(芳硫基)巴豆酸,而不是据报道,S-苯基 3-硫代丁烷 (1)。在三乙胺的存在下,由苯硫醇和双烯酮制备化合物 1a-k 作为硫代香豆素的前体。已检查 1 与各种缩合剂的反应以制备 2H-1-benzothiopyran-2-ones(硫香豆素)。发现通过 1 与无水氯化铝反应可以方便地制备 4-甲基(硫代香豆素),产率为 16-48%。当 1 用 PPA 处理时,以 5-66% 的产率优先获得异构体 2-甲基(硫色酮),并且化合物 2 作为中间体被分离出来。