Patent ID: 7553862

Claim:
A compound of formula I wherein R 1 is —(CH 2 ) n -aryl or —(CH 2 ) n -heteroaryl, wherein such groups are unsubstituted or substituted by one or more substituents selected from the group consisting of halogen, lower alkyl substituted by halogen, lower alkoxy, lower alkyl, cyano, nitro, —O-lower alkyl substituted by halogen and morpholinyl; R 2 is —(CH 2 ) n -aryl or —(CH 2 ) n -heteroaryl, wherein such groups are unsubstituted or substituted by one or more substituents selected from the group consisting of lower alkyl, lower alkoxy, halogen and —N(lower alkyl) 2 ; R 3 is hydrogen or lower alkyl; R 4 is —(CH 2 ) n -aryl or —(CH 2 ) n -heteroaryl, wherein such groups are unsubstituted or substituted by one or more substituents selected from the group consisting of halogen and lower alkoxy, or is lower alkyl; or R 3 and R 4 form together with the N-atom to which they are attached a heterocyclic ring; and n is 0, 1 or 2; or a pharmaceutically acceptable acid addition salt thereof.