1. A compound of the general formula wherein R / R are independently of one another hydrogen, (CR) -cycloalkyl optionally substituted by lower alkyl or hydroxy, or are lower alkyl or heterocycloalkyl, and o is 0 or 1 and R may be the same or different and are hydrogen or lower alkyl or R and R can form, together with the N atom to which they are attached, a heterocycloalkyl group selected from the group consisting of pyrrolidinyl, piperidinyl, 3-aza-bicyclo [3.1.0] hex-3-yl or 2-aza-bicyclo [3.1. 0] hex-2-yl which are optionally substituted by hydroxy R 1 is lower alkyl, lower alkyl, lower alkoxy or cycloalkyl R 4 is hydrogen, lower alkyl, substituted by halogen, lower alkyl or lower alkoxy R 3 is lower alkyl, substituted halogen, lower alkyl or lower alkoxy, X is -O- or -CH-, X is -O- or -CH- with the proviso that one of X or X is always -O- and the other is -CH-, or a pharmaceutically acceptable acid addition salt, a racemic mixture or the corresponding enantiomer and / or optical isomer. The compound of the formula I-1 encompassed by the formula I according to claim 1, wherein R / R is independently of one another hydrogen, (CR) -cycloalkyl optionally substituted by lower alkyl or hydroxy or are lower alkyl or heterocycloalkyl, and o is 0 or 1 and R may be the same or different and are hydrogen or lower alkyl or R and R can form together with the N atom to which they are attached a heterocycloalkyl group selected from the group consisting of pyrrolidinyl X is -O- or -CH- X is -O- or -CH- with the proviso that one of X or X is always -O- and the other is -CH-, or a pharmaceutically acceptable acid addition salt, a racemic mixture or the corresponding enantiomer and / or optical isomer. The compound of the formula I-1 encompassed by the formula I according to claim 1, wherein R / R is independently of one another hydrogen, (CR) -cycloalkyl optionally substituted by lower alkyl or hydroxy or are lower alkyl or heterocycloalkyl, and o is 0 or 1 and R may be the sam
