A method has been developed for the synthesis of a new heterocyclic system III. When 2-β-chloroethoxybenzyl chloride (XI) was heated with thiourea in alcohol solution, S-(2-β-chloroethoxybenzyl)isothiuronium chloride (XII) was formed which on cleavage with aqueous alkali in high dilution yielded 2,3-dihydrobenzo(f)-1,4-oxathiepin (III). Derivatives of III with substituents such as methyl, t-butyl, chlorine, and nitro in the 7 and 9 positions were prepared in high yields from the corresponding substituted 2-β-chloroethoxybenzyl chlorides. The presence of substituents in the position ortho to the chloroethoxy group of XII had no retarding effect on the cyclization to XIV.
已开发出一种合成新杂环系统 III 的方法。当 2-β-氯乙氧基苄氯(XI)在醇溶液中与硫脲加热时,形成了 S-(2-β-氯乙氧基苄)异硫脲盐酸盐(XII),在高稀释条件下与水性碱裂解,生成了2,3-二氢苯并(f)-1,4-噁硫杂环(III)。通过对应的取代的 2-β-氯乙氧基苄氯制备了 III 的衍生物,这些衍生物在 7 和 9 位置带有甲基、叔丁基、氯和硝基等取代基,并且产率很高。XII 的氯乙氧基基团正交位上的取代基对生成 XIV 的环化反应没有延缓作用。