Loratadine Impurity I synthesis

Yield:-

Steps:

P.37.A A.
A. 4-(8-Chloro-11H-Benzo[5,6]Cyclohepta[1,2-b]Pyridin-11-Ylidene)-1-(Ethoxycarbonyl)-Piperidine STR153 The preparation of the starting material for this reaction was described in The Journal of Organic Chemistry, 1990, 55, pp. 3341-3350 by Piwinski, et al. By substituting in Preparative Example 2, 8-chloro-11H-benzo[5,6]-cyclohepta[1,2-b]pyridin-11-one for 9-fluoro-5,6-dihydro-11H-benzo[5,6]-cyclohepta[1,2-b]pyridin-11-one and employing basically the same methods as steps D through F of Preparative Example 2, one obtains the title compound (mp 154.7°-155.5° C.

References:

Schering Corporation US5700806, 1997, A