Patent ID: 7579478

Claim:
A process for purifying a compound of Formula I: wherein: R 1 is alkenyl of 2-7 carbon atoms; wherein the alkenyl moiety is optionally substituted with one or more substituents independently selected from hydroxyl, —CN, halogen, trifluoroalkyl, trifluoroalkoxy, —COR 5 , —CO 2 R 5 , —NO 2 , CONR 5 R 6 , NR 5 R 6 and N(R 5 )COR 6 ; R 2 and R 2a are each, independently, hydrogen, hydroxyl, halogen, alkyl of 1-6 carbon atoms, alkoxy of 1-4 carbon atoms, alkenyl of 2-7 carbon atoms, alkynyl of 2-7 carbon atoms, trifluoroalkyl of 1-6 carbon atoms, or trifluoroalkoxy of 1-6 carbon atoms; wherein the alkyl, alkenyl, or alkynyl moieties are each optionally substituted with one or more substituents independently selected from hydroxyl, —CN, halogen, trifluoroalkyl, trifluoroalkoxy, —COR 5 , —CO 2 R 5 , —NO 2 , CONR 5 R 6 , NR 5 R 6 and N(R 5 )COR 6 ; R 3 , and R 3a are each, independently, hydrogen, alkyl of 1-6 carbon atoms, alkenyl of 2-7 carbon atoms, alkynyl of 2-7 carbon atoms, halogen, alkoxy of 1-4 carbon atoms, trifluoroalkyl of 1-6 carbon atoms, or trifluoroalkoxy of 1-6 carbon atoms; wherein the alkyl, alkenyl, or alkynyl moieties are each optionally substituted with one or more substituents independently selected from hydroxyl, —CN, halogen, trifluoroalkyl, trifluoroalkoxy, —COR 5 , —CO 2 R 5 , —NO 2 , CONR 5 R 6 , NR 5 R 6 and N(R 5 )COR 6 ; R 5 , R 6 are each, independently, hydrogen, alkyl of 1-6 carbon atoms, aryl of 6-10 carbon atoms; and X is O; from a mixture comprising said compound and at least one impurity, comprising the steps of: a) recrystallizing said compound from a solution comprising acetone and acetonitrile to provide an initially purified product; b) dissolving said intially purified product in a solution comprising ethyl acetate; c) treating said solution comprising ethyl acetate with a clarifying agent to form a clarified solution; d) optionally concentrating said clarified solution to form a concentrated clarified solution or slurry; e) adding a nonpolar solvent to said clarified solution or said clarified concentrated solution or slurry to form a mixed solvent solution or slurry; and f) collecting the purified compound from said mixed solvent solution or slurry.