Patent ID: 7176235

Claim:
A purified compound of formula (I) or a pharmaceutically acceptable salt or solvate thereof wherein: R 1 , R 2 , and R 3 , are each independently H, C 1 –C 5 alkyl, C 2 –C 5 alkenyl, C 2 –C 5 alkynyl, aryl or alkylaryl; R 4 is H, C 1 –C 5 alkyl, C 1 –C 5 hydroxyalkyl, C 1 –C 5 haloalkyl, aryl, —C(═O)R 6 , —C(═O)OR 6 , or —NR 6 R 7 where R 6 and R 7 are each independently hydrogen, C 1 –C 5 aliphatic, aryl or alkylaryl; R 5 is H, C 1 –C 5 alkyl, C 1 –C 5 alkoxy, C 2 –C 5 alkenyl, C 2 –C 5 alkynyl, aryl or alkylaryl; W is O, NR 8 where R 8 is hydrogen, C 1 –C 5 alkyl, C 2 –C 5 alkenyl, C 2 –C 5 alkynyl, aryl or alkylaryl; X is O, CH 2 or a carbon-carbon bond; Y is absent or a C 1 –C 5 alkyl, C 2 –C 5 alkenyl, or C 2 –C 5 alkynyl; and Ar is aryl; provided that when W is O at least one of R 1 , R 3 , or R 5 is other than H.