Heterocyclic systems containing bridgehead nitrogen atom: Part LXVI. Studies of orientation of cyclization in the synthesis of 8-fluorothiazolo[3,2-]benzimidazol-3(2)-one
作者:Rajinder Dahiya、H.K. Pujari
DOI:10.1016/s0022-1139(00)82753-0
日期:1989.2
2-Fluoro-6-nitroaniline, obtained by nitration of 2-fluoroacetanilide, on reduction with Raney nickel and hydrazine hydrate followed by treatment of the resulting diamine with carbon disulphide in situ gives 4-fluorobenzimidazolyl-2-thione. This thione on condensation with chloroacetic acid gives 4-fluorobenzimidazol-2-thiolacetic acid which on cyclization with a mixture of acetic anhydrite and pyridine
通过用阮内镍和水合肼还原将2-氟乙酰苯胺硝化而得到的2-氟-6-硝基苯胺,然后用二硫化碳原位处理所得的二胺,得到4-氟苯并咪唑基-2-硫酮。该硫酮与氯乙酸缩合后得到4-氟苯并咪唑-2-硫代乙酸,将其与乙酸无水石膏和吡啶的混合物环化后,得到8-氟噻唑[3,2-a]苯并咪唑-3(2H)-一个而不是另一个可能的异构体5-氟噻唑[3,2-a]苯并咪唑-3(2H)-1 H-NMR光谱显示。4-氟苯并咪唑基-2-硫酮与1,2-二溴乙烷的缩合产生2,3-二氢-8-氟噻唑[3,2-a]苯并咪唑和对-双-(4-氟苯并咪唑-2-基巯基)乙烷。