Patent ID: 7465825

Claim:
A compound of the formula: or a pharmaceutically acceptable salt thereof, wherein R 28 is (i) hydrogen, (ii) adamantanyl, (iii) dibenzofuranyl, (iv) C 1 -C 4 alkyl, (v) dibenzothiophenyl, or (vi) phenyl substituted with one or two C 1 -C 3 alkoxy or C 1 -C 2 acyl, or with one phenoxy; R 29 is (i) hydrogen, (ii) adamantanyl, (iii) dibenzofuranyl, (iv) C 1 -C 4 alkyl, (v) dibenzothiophenyl, or (vi) phenyl substituted with one or two C 1 -C 3 alkoxy or C 1 -C 2 acyl, or with one phenoxy; provided that one of R 28 and R 29 is adamantyl, dibenzofuranyl, dibenzothiophenyl, or phenyl substituted with one or two C 1 -C 3 alkoxy or C 1 -C 2 acyl, or with one phenoxy; provided that one of R 28 and R 29 is hydrogen or C 1 -C 4 alkyl; R 20 and R 21 are independently hydrogen or halogen; L 1 is C 1 -C 4 alkyl, wherein the alkyl group is optionally substituted with —CH 3 ; each R 10 is independently H, halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, C 1 -C 4 haloalkyl, C 1 -C 4 haloalkoxy, NO 2 , NH 2 , NH(C 1 -C 6 )alkyl, or N(C 1 -C 6 )alkyl(C 1 -C 6 )alkyl; and n is 0, 1, or 2.