The addition compound of 8-chloro-6, 11-dihydro-11-(4-piperidylidene)-5 H-benzo [5, 6] cyclohepta [1, 2-b] pyridine (descarboethoxyloratadine, desloratadine) with CO2, in molar ratio 2: 1, is described. This unique form of desloratadine drug substance can be prepared in exceedingly high purity by a simple process from crude desloratadine. The addition compound is a useful intermediate in the manufacturing process of desloratadine Form I ...
