Pyrido [2,1-a] isoquinoline derivatives

A ompound of formula (I)

• 11
• wherein
• R1 is lower alkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, or lower alkyl substituted by cycloalkyl, aryl, substituted aryl, heteroaryl or substituted heteroaryl;
• R2, R3 and R4 are each independently hydrogen, halogen, hydroxy, lower alkyl, lower alkoxy or lower alkenyl, wherein lower alkyl, lower alkoxy and lower alkenyl are optionally substituted by lower alkoxycarbonyl, aryl, substituted aryl, heterocyclyl or substituted heterocyclyl.
• R5 is hydrogen, fluorine, lower alkyl, aryl or substituted aryl;
• R6 is hydrogen, lower alkyl or hydroxy-lower alkyl, or
• R5 and R6 together with the carbon atoms to which they are attached form a five or six membered saturated carbocyclic ring;
• R7 is hydrogen, fluorine or lower alkyl;
• and pharmaceutically acceptable salts thereof;
• with the exception of rac-3β-Isobutyl-9,10-dimethoxy-1,3,4,6,7,11bβ-hexahydro-2H-pyrido[2,1-a]isoquinolin-2β-ylamine dihydrochloride and rac-3β-Isobutyl-9,10-dimethoxy-1,3,4,6,7,11bβ-hexahydro-2H-pyrido[2,1-a]isoquinolin-2α-ylamine dihydrochloride.