Patent ID: 7553845

Claim:
A compound of formula I: wherein: R at 6-, 7- or 8-position of the indolizine ring is hydrogen, halogen, methyl, hydroxy, (C 1 -C 5 )-alkoxy, carboxy, (C 2 -C 6 )-alkoxycarbonyl, —NR 5 R 6 , —NH—SO 2 -Alk, —NH—CO-Alk, —NH—CO 2 -Alk, —O-Alk-COOR 7 , —O-Alk-NR 5 R 6 , —O—(CH 2 ) n —Ph, or —CO—NR 5 R 6 ; R 1 is (C 1 -C 5 )-alkoxy, carboxy, (C 2 -C 6 )-alkoxycarbonyl, or Ph; R 2 is (C 1 -C 5 )-alkyl, (C 3 -C 6 )-cycloalkyl, or phenyl, wherein the phenyl is optionally substituted with one or more halogen, or (C 1 -C 5 )-alkoxy; R 3 and R 4 independently are hydroxy, (C 1 -C 5 )-alkoxy, amino, carboxy, (C 2 -C 6 )-alkoxycarbonyl, nitro, —NR 5 R 6 , —NH—CO-Alk, —NH—CO—CF 3 , —CO—NR 5 R 6 , or —CO—NHOH; Alk is (C 1 -C 5 )-alkyl or (C 1 -C 5 )-alkylene; n is an integer from 0 to 5; R 5 and R 6 independently are hydrogen, (C 1 -C 5 )-alkyl, or benzyl; R 7 is hydrogen or (C 1 -C 5 )-alkyl; and Ph is phenyl optionally substituted with one or more halogen, (C 1 -C 5 )-alkoxy, carboxy, or (C 2 -C 6 )-alkoxycarbonyl; provided that when R is hydrogen, and R 3 and R 4 independently are not —CO—NR 5 R 6 or —CO—NHOH, then R 1 is not (C 1 -C 5 )-alkoxy, carboxy, or (C 2 -C 6 )-alkoxycarbonyl; or a pharmaceutically acceptable salt thereof.