A Novel Convenient Synthesis of 1,3,4-Oxadiazol-2-ones and -thiones from N-tert-Butyldiacylhydrazines
作者:Mark J. Mulvihill、Duyan V. Nguyen、Brian S. MacDougall、Damian G. Weaver、William D. Mathis
DOI:10.1055/s-2001-17703
日期:——
An attractive, novel, convenient process for the preparation of 3,5-disubstituted-3H-[1,3,4]-oxadiazol-2-ones and -thiones from the reaction of various equivalent and non-equivalent N-tert-butyldiacylhydrazines with potassium tert-butoxide followed by treatment with phosgene or thiophosgene, respectively, has been discovered. The 3,5-disubstituted-3H-[1,3,4]-oxadiazol-2-ones and -thiones are confirmed both analytically and chemically. Various equivalent and non-equivalent N-tert-butyldiacylhydrazines are conveniently synthesized from the reaction of tert-butylhydrazine hydrochloride in the presence of i-Pr2NEt, with acid chloride #1 followed by subsequent treatment with acid chloride #2. Both the syntheses of 3,5-disubstituted-3H-[1,3,4]-oxadiazol-2-ones and -thiones, as well as N-tert-butyldiacylhydrazines, are easily performed on multigram scales.
我们发现了一种有吸引力的、新颖的、方便的制备 3,5-二取代-3H-[1,3,4]-噁二唑-2-酮和-硫酮的工艺,该工艺是由各种等量和非等量的 N-叔丁基二乙酰肼与叔丁醇钾反应,然后分别用光气或硫代光气处理。3,5-二取代-3H-[1,3,4]-噁二唑-2-酮和-硫酮在分析和化学上都得到了证实。在 i-Pr2NEt 存在下,通过叔丁基肼盐酸盐与酸性氯化物 #1 的反应,然后再与酸性氯化物 #2 处理,可以方便地合成各种等效和非等效的 N-叔丁基二乙酰肼。3,5-二取代-3H-[1,3,4]-噁二唑-2-酮和-硫酮以及 N-叔丁基二乙酰肼的合成都很容易以多克为单位进行。