Patent ID: 7553972

Claim:
A compound of the formula wherein R 1 is methyl or ethyl optionally substituted with one or two groups independently selected from hydroxyl, (C 6 -C 7 )cycloalkyl and phenyl; wherein said (C 6 -C 7 )cycloalkyl and phenyl may be optionally substituted by one to three radicals independently selected from hydroxyl, halo, methyl and phenyl; R 2 is halo; R 3 is an optionally substituted carbon linked 6-membered heteroaryl or heterocyclyl group selected from the group of: wherein R 4 is independently selected from the group consisting of hydrogen, methyl and (C 1 -C 6 )alkoxy; wherein the molecular weight of said compound of formula I is less than 700 AMU; or a pharmaceutically acceptable salt thereof.