The present invention relates to a compound of formula (IA), wherein G1 is lower alkyl lower alkyl substituted by one or more halogens cycloalkyl tetrahydropyran-4-yl phenethyl phenethyl substituted by one or more halogens phenoxymethyl phenoxymethyl substituted by one or more halogens benzyloxyethyl benzyloxy-ethyl substituted by one or more halogens or is &mdashNR2R3 R2 is hydrogen or lower alkyl R3 is lower alkyl tetrahydropyran-4-yl &mdashCH2-cycloalkyl or cycloalkyl optionally substituted by lower alkyl substituted by one or more halogens or R2 and R3 form together with the N-atom to which they are attached a heterocycloalkyl group with 4 or 5 carbon atoms, which is optionally substituted by one or more substituents selected from halogen or lower alkyl substituted by one or more halogens X is &mdashCH2&mdashor &mdash(CH2)2&mdash Ar is phenyl or pyridinyl R4 is halogen lower alkyl lower alkyl substituted by one or more halogens or lower alkoxy n is 1 or 2 or to a pharmaceutically active salt thereof, to a stereoisomeric form, including an individual diastereoisomer or enantiomer of the compound of formula (IA) as well as to a racemic or non-racemic mixture thereof. The present invention also relates to the use of a compound of formula (IA) for treating certain neurodegenerative disorders characterized by cytotoxic TAU misfolding and/or aggregation.
