A process and new oxazolinic intermediates for the preparation of 4-(8-chloro-5,6-dihydro-11H-benzo-[5,6]-clohepta-[1,2-b]-pyridin-11-ylidene)-1-piperidinecarboxylic acid ethyl ester (loratadine) is described. The process starts from 2-(4,4-dimethyl-4,5-dihydrooxazol-2-yl)-3-methyl-pyridine, a new intermediate to obtain loratadine. 2-(4,4-dimethyl-4,5-dihydrooxazol-2-yl)-3-methyl-pyridine is condensed with 3-chloro-benzyl-chloride and the resultant product is treated with Grignard reagent of 4-chloro-N-methyl-piperidine. [3-(2-(3-chloro-phenyl)-ethyl]-pyridin-2-yl]-1-(methyl-piperidin-4-yl)-methanone is obtained for subsequent hydrolysis. Starting from this last compound it is possible to obtain loratadine with known methods.
本文描述了一种制备4-(8-
氯-5,6-二氢-11H-苯并[5,6]环庚[1,2-b]
吡啶-11-基)-
1-哌啶羧酸乙酯(洛拉他定)的过程和新的
噁唑啉中间体。该过程从2-(4,4-二甲基-4,5-二氢
噁唑-2-基)-3-甲基-
吡啶开始,这是一种获得洛拉他定的新中间体。2-(4,4-二甲基-4,5-二氢
噁唑-2-基)-3-甲基-
吡啶与
3-氯苄基氯化物缩合,得到的产物经过4-
氯-
N-甲基哌啶格氏试剂处理。随后进行
水解反应,得到[3-(2-(3-
氯苯基)乙基]-
吡啶-2-基]-1-(甲基
哌啶-4-基)-甲酮。从这个化合物开始,可以用已知的方法制备洛拉他定。