Patent ID: 8349858

Claim:
A compound having the formula: or a pharmaceutically acceptable salt, thereof, wherein: R 1 is —C 1 -C 6 alkyl or -alkylene-O—C 1 -C 6 alkyl; R 2 is alkyl, aryl, -alkylene-aryl, heterocycloalkyl or heteroaryl, any of which may be optionally substituted with R 5 ; R 3 is alkyl, -alkylene-aryl, cycloalkyl, -alkylene-cycloalkyl or -alkylene-heterocycloalkyl, wherein an aryl, cycloalkyl or heterocycloalkyl group can be optionally substituted with R 7 ; each occurrence of R 4 is independently H or —C 1 -C 6 alkyl, or both R 4 groups together with the carbon atom to which they are attached, join to form a 3- to 7-membered cycloalkyl group, which can be optionally fused with a benzene ring; R 5 represents from 1 to 3 groups, each independently selected from alkenyl, alkynyl, aryl, heterocycloalkyl, heteroaryl, halo, —CN, —C(O)OR 6 , —C(O)R 6 , —C(O)N(R 6 ) 2 , —S(O) 2 NHR 6 , —OH, —O-alkyl, haloalkyl, —O-haloalkyl and —NHC(O)N(R 6 ) 2 , where an aryl, heterocycloalkyl or heteroaryl group may be optionally substituted with up to 3 groups, each independently selected from —C 1 -C 6 alkyl, halo, —C(O)OR 6 and —C(O)N(R 6 ) 2 ; each occurrence of R 6 is independently H, —C 1 -C 6 alkyl, aryl or heterocycloalkyl, wherein an aryl or heterocycloalkyl group can be optionally substituted with up to 3 groups, each independently selected from alkyl, —O-alkyl, halo, —CN, haloalkyl, -alkylene-C(O)N(R 8 ) 2 , —C(O)N(R 8 ) 2 , —C(O)OR 8 , —C(O)-heterocycloalkyl, —C(O)-alkyl or —N(R 8 ) 2 ; R 7 represents from 1 to 3 groups, each independently selected from —C 1 -C 6 alkyl, halo, aryl, —N(R 8 ) 2 , —C(O)OR 8 , —C(O)N(R 8 ) 2 and haloalkyl; and each occurrence of R 8 is independently H, —C 1 -C 6 alkyl or aryl, provided that when one of R 4 is hydrogen, and the other is ethyl or propyl, and R 1 is ethyl, then R 2 and R 3 both cannot be benzyl.