Method for producing 4-chloro-5-amino-2-phenyl-3(2H)-pyridazinone from 4,5-dichloro-2-phenyl-3(2H)-pyridazinone and ammonia
申请人:BASF Aktiengesellschaft
公开号:EP0028359A1
公开(公告)日:1981-05-13
4-Chloro-5-amino-2-phenyl-3(2H)-pyridazinone is prepared from 4,5-dichloro-2-phenyl-3(2H)-pyridazinone and ammonia in high yield and substantially free from 4-amino-5-chloro- 2-phenyl-3(2 H)-pyridazinone in a method comprising reacting 4,5-dichloro-2-phenyl- 3(2H)-pyridazinone with aqueous ammonia in the presence of a catalyst (a phenolic compound) which is capable of selectively exchanging the 5-chlorine atom in 4,5-dichloro-2- phenyl-3(2H)-pyridazinone with a leaving group of such a nature that the resulting intermediate compound is capable of aklylating ammonia to 4-chloro-5-amino-2- phenyl-3(2H)-pyridazinone in high yield in the reaction medium, thereby regeneratingthe catalyst. The end product is isolated by filtration after the reaction and washed with water, and the mother liquor plus the wash water are used as reaction medium for the next batch.
4-氯-5-氨基-2-苯基-3(2H)-哒嗪酮是由 4,5-二氯-2-苯基-3(2H)-哒嗪酮和氨以高产率制备的,并且基本上不含 4-氨基-5-氯-2-苯基-3(2H)-哒嗪酮,制备方法包括将 4、5-二氯-2-苯基-3(2H)-哒嗪酮与氨水反应,反应过程中催化剂(一种酚类化合物)能够选择性地交换4,5-二氯-2-苯基-3(2H)-哒嗪酮中的5-氯原子、5-二氯-2-苯基-3(2H)-哒嗪酮中的 5-氯原子与离去基团进行选择性交换,交换后的中间化合物能够在反应介质中以高产率将氨烷基化为 4-氯-5-氨基-2-苯基-3(2H)-哒嗪酮,从而使催化剂再生。反应结束后通过过滤分离出最终产物并用水洗涤,母液和洗涤水用作下一批反应的反应介质。