| 摘要 |
The invention comprises the acid addition compounds of the formula <FORM:0988784/C2/1> and compounds of the formula <FORM:0988784/C2/2> (wherein R is a five-membered heterocyclic ring containing nitrogen and sulphur as heteroatoms and either unsubstituted or C1- 5-alkyl substituted, and each of R1 and R2 is a hydrogen atom or a C1-alkyl or -alkoxy group), together with their preparation by reacting a compound of the formula <FORM:0988784/C2/3> with a cyano-substituted five-membered hetero-cyclic ring compound containing nitrogen and sulphur in the presence of a Friedel-Crafts catalyst and, separately, reacting the amidine from the first stage with hydroxylamine to give the hydroxyamidine; and a process for the preparation of 2-R-benzimidazole by reacting an appropriate 4-hydroxyamidine, optionally prepared by the above process, with an alkyl or aryl sulphonyl halide. 4-Cyanothiazole is prepared by reacting thiazole - 4 - carboxylic acid with thionyl chloride to give thiazole-4-carboxylic acid chloride, converting this to the carboxamide and dehydrating this with phosphorus pentoxide. |
