alkyl u2014 chr u2014 nhc o lower alkyl u2014 chr u2014 nhc o o lower alkyl substituted by halogen u2014 chr u2014 nhc o phenyl optionally substituted by halogen u2014 chr u2014 nhch 2 ch 2 o lower alkyl u2014 chr u2014 nh u2014 s o 2 phenyl optionally substituted by halogen or lower alkyl u2014 chr u2014 nh u2014 s o 2 u2014 ch 2 phenyl optionally substituted by halogen u2014 chr u2014 nh u2014 s o 2 lower alkyl ch 2 piperidin 1 yl ch 2 morpholinyl or indole 2 carboxylic acid 3 4 difluoro phenyl amide r and r u2032 are each independently hydrogen lower alkyl benzyl or hydroxy and r 5 is hydrogen halogen lower alkyl substituted by hydroxy or is lower alkyl hydrogen lower alkyl lower alkyl substituted by halogen u2014 crr u2032 phenyl which is unsubstituted or substituted by one or more halogen lower alkyl lower alkyl substituted by halogen lower alkoxy substituted by halogen or lower alkoxy u2014 ch 2 u2014 c o nh phenyl optionally substituted by halogen u2014 chr u2014 nhc o o lower alkyl u2014 chr u2014 nhc o o lower alkyl substituted by halogen u2014 chr u2014 nhc o u2014 ch 2 phenyl optionally substituted by halogen u2014 chr u2014 nhc o phenyl optionally substituted by halogen u2014 chr u2014 nh u2014 s o 2 phenyl optionally substituted by halogen or lower alkyl u2014 chr u2014 nh u2014 s o 2 u2014 ch 2 phenyl optionally substituted by halogen or u2014 chr u2014 nh u2014 s o 2 lower alkyl r and r u2032 are.