| 摘要 |
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-ylide-ne)-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-dihydro-oxazol-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. |
