2-oxa-5-azabicyclo[2.2.1]heptan-3-yl derivatives

A compound of formula I

• wherein
• L is a bond, —C(O)NH—, —NHC(O)—, —CH2NHC(O)—, CH2C(O)NH—, —CH2NH—, —NH— or —NHC(O)NH—;
• R1 is hydrogen, lower alkyl, halogen, lower alkoxy-alkyl, lower alkoxy substituted by halogen, lower alkyl substituted by halogen, phenyl or heteroaryl wherein said heteroaryl is selected from the group consisting of pyridinyl, pyrimidinyl, pyrazinyl and pyrazolyl, and wherein said phenyl or said heteroaryl are optionally substituted by one, two or three substituents selected from the group consisting of halogen, lower alkyl, lower alkoxy, lower alkyl substituted by halogen, lower alkoxy substituted by halogen, cycloalkyl and O—CH2-cycloalkyl;
• X is CH or N;
• or a pharmaceutically suitable acid addition salt thereof and an enantiomer, a racemic mixture or a mixture of enantiomers.