The present invention relates to compounds of formula I wherein R<；SUP>；1 <；/SUP>；is selected from the group consisting of hydrogen or lower alkyl； R<；SUP>；2 <；/SUP>；is hydrogen, lower alkyl, lower alkenyl, lower alkyl substituted by hydroxy, lower alkyl substituted by halogen, -(CH<；SUB>；2<；/SUB>；)<；SUB>；x<；/SUB>；-S-lower alkyl, -(CH<；SUB>；2<；/SUB>；)<；SUB>；x<；/SUB>；-O-lower alkyl, -(CH<；SUB>；2<；/SUB>；)<；SUB>；x<；/SUB>；-NHC(O)O-lower alkyl, -(CH<；SUB>；2<；/SUB>；)<；SUB>；x<；/SUB>；-aryl, and -(CH<；SUB>；2<；/SUB>；)<；SUB>；x<；/SUB>；-heteroaryl； each R<；SUP>；3 <；/SUP>；is selected from the group consisting of hydrogen, lower alkyl, lower alkoxy, halogen, hydroxy, lower alkyl substituted by halogen, -O-(CH<；SUB>；2<；/SUB>；)<；SUB>；m<；/SUB>；-aryl, -O-(CH<；SUB>；2<；/SUB>；)<；SUB>；m<；/SUB>；-heteroaryl, -(CR<；SUB>；2<；/SUB>；)<；SUB>；m<；/SUB>；-aryl, and -(CR<；SUB>；2<；/SUB>；)<；SUB>；m<；/SUB>；-heteroaryl； each R is selected from the group consisting of hydrogen, lower alkyl and hydroxy； Ar is selected from the group consisting of phenyl, pyrimidin-2-yl, pyrimidin-4-yl and pyridin-3-yl； n is 0, 1 or 2； x is 0, 1, 2 or 3； m is 0 or 1； and to their pharmaceutically active salts.
