Patent ID: 7217838

Claim:
A compound of formula (I), or a pharmaceutically acceptable salt, prodrug, salt of a prodrug, or a combination thereof wherein one of A 1 , A 2 , A 3 and A 4 is selected from the group consisting of alkylcarbonyl, alkylsulfonyl, and, —S(O) 2 —N(R 5 R 6 ), with the exception that the remaining members of the group consisting of A 1 , A 2 , A 3 and A 4 are each individually selected from the group consisting of hydrogen and alkyl; D is a bond; E is selected from the group consisting of a cycloalkyl and aryl, wherein R 4 and E together with the atoms to which they are attached form a cycloalkyl ring; R 1 is selected from the group consisting of hydrogen and alkyl; R 2 is selected from the group consisting of hydrogen and alkyl; R 3 and R 4 are each independently selected from the group consisting of hydrogen alkyl and cycloalkyl, or R 3 and R 4 together with the atom to which they are attached form a cycloalkyl ring; and R 5 and R 6 are each independently selected from the group consisting of hydrogen, and alkyl.