The present invention describes a new process for the preparation of omeprazole, lansoprazole and pantoprazole of formula (XXI), (XXXIII), and which involves the formation of pyridines N-oxide using a rhenium compound as a catralyst, followed by nitration of the 4-position with nitric acid fuming in presence of a claycop. The chlorination of the 2-methyl group of pyridine was achieved by using the POCI3/Et3N, which allowed the preparation of the derivates 2-chloromethylpyridines in only one step. These derivates reacted with the mercaptobenzimidazolic derivatives in presence of ultra-sonic radiation, giving the thioethers. The oxidation of these thioethers was done with several oxidizing agents and the required anti-ulcer compounds were obtained after the substitution of nitro group by the corresponding OR groups.
本发明描述了一种制备式(XXI),(XXXIII)的
奥美拉唑,
兰索拉唑和
泮托拉唑的新工艺,其中涉及使用一种
铼化合物作为催化剂形成
吡啶N-氧化物,随后在存在粘土
铜的情况下使用
硝酸烟雾硝化4位位置。使用POCI3 / Et3N实现了
吡啶的2-甲基基团的
氯化,从而仅通过一步即可制备出2-
氯甲基
吡啶衍生物。这些衍
生物在超声辐射下与巯基
苯并咪唑衍
生物反应,产生
硫醚。这些
硫醚经过多种氧化剂氧化后,通过用相应的OR基团取代硝基团来得到所需的抗溃疡化合物。