A PROCESS FOR THE PREPARATION OF A COMBINATION OF POLYMORPHS 1and 2 OF DESLORATADINE AND DESLORATADINE POLYMORPHS 1 and 2 COMBINATION PREPARED BY THE SAME

摘要

(a) dissolving Loratadine (ethyl 4-(8-chloro-5, 6-dihydro-11H-benzo[5,6]cyclohepta [1,2-b]pyridin-11-ylidene)piperidine-1-carboxylate in an alcoholic solvent having C1 to C5 carbon atoms (straight or branched chains)10%w/v to 30%w/v solution preferably around 20%w/v solution; (b) reacting Loratadine solution with aqueous solution of Potassium hydroxide at 50ºC to 150ºC preferably 80ºC to 85ºC for 2 to 15 hours preferably for 7 to 8 hours under pressure of 0.5kg/cm² to 5 kg/cm² preferably 2kg/cm² in an autoclave (20 moles to 200 moles); (c) releasing the pressure of the above reaction of step (b) and filtering the solution with solvent recovery under vacuum; (d) diluting the residue of step (c) with brine followed by concentration and extracting ethyl acetate to isolate crude Desloratadine; (e) Crystallization of crude Desloratadine of step (d) by dissolving in acetonitrite followed by filtration and cooling the filtrate at 0 to 5ºC for separating out Desloratadine in crystalline form; (f) Filtering out the wet crystals of Desloratadine polymorphs 1 and 2 combination and drying the said crystals in an oven at 50 to 100º c preferably at 70ºC for 4 to 8 hours preferably at 6 hours.