Arlethynyl Derivatives

The compound of formula I-C1

• wherein
• U is ═N— or ═C(R5)—;
• V is —CH═ or —N═;
• W is ═CH— or ═N—;
• with the proviso that only one of U, V or W is nitrogen.
• R5 is hydrogen, methyl or halogen;
• R6 is hydrogen or lower alkyl;
• R1 is phenyl or heteroaryl, each of which is optionally substituted by one or two substituents, selected from halogen, lower alkyl and lower alkoxy;
• R2 and R2′ are each independently hydrogen, lower alkyl, hydroxy, lower alkoxy, C3-C6-cycloalkyl, or CH2-lower alkoxy, or together with the carbon atom to which they are attached form a C3-C6-cycloalkyl group or a ring containing —CH2OCH2—;
• and
• R3 and R3′ are each independently hydrogen, lower alkyl, or CH2-lower alkoxy or together with the carbon atom to which they are attached form a C3-C6-cycloalkyl group;
• or R3 and R2 together with the carbon atom to which they are attached form a C3-6-cycloalkyl group or a ring containing —(CH2)2OCH2—;
• or R6 and R2 together with the carbon atom and the nitrogen atom to which they are attached form a C3-6-cycloalkyl group;
• or a pharmaceutically acceptable acid addition salt, a racemic mixture, an enantiomers, an optical isomer and/or stereoisomer thereof.