The invention provides a method for the production of a pyrazolo(1,5-a)benzimidazole of the general formula (A): ##STR1## wherein R is a substituted or unsubstituted alkyl or aryl group, and R.sup.1 -R.sup.4 =R, H, halogen, OR, COOR, CONHR, SO.sub.2, NO.sub.2 NHR, NR.sub.2, or CN, and X is hydogen or a reactive group releasable on coupling with an oxidized color developer, wherein the invention provides reacting a 2-amino or 2-mercapto substituted benzimidazole to form a triazepinone or a thiadiazino derivative respectively, ring contracting said triazepinone or thiadiazino derivative to give the corresponding 2-methylpyrazolobenzimidazole product, and subsequently removing the substituents at the -3 or -4 positions to provide a compound of the general formula (1).
本发明提供了一种制备通式(A)的
吡唑并[1,5-a]
苯并咪唑的方法:##STR1## 其中R是取代或未取代的烷基或芳基基团,R.sup.1-R.sup.4 = R、H、卤素、OR、COOR、CONHR、SO.sub.2、NO.sub.2 NHR、NR.sub.2或CN,X为氢或可在与氧化色发展剂偶联时释放出的反应性基团,该方法包括反应2-
氨基或2-巯基取代
苯并咪唑,形成三唑烷酮或
噻二唑衍
生物,分别环收缩所述三唑烷酮或
噻二唑衍
生物以给出相应的2-甲基
吡唑并
苯并咪唑产物,并随后去除-3或-4位置上的取代基,以提供通式(1)的化合物。