l optionally substituted by hydroxy, alkylamino, alkoxy, oxo, aryl or cycloalkyl: alkyl, such as methyl or ethyl, or alkylaminoalkyl, such as methylaminomethyl or dimethylaminomethyl;for hydroxyalkyl: hydroxymethyl;for alkoxyalkyl: methoxymethyl;for alkoxycarbonyl: methoxycarbonyl or ethoxycarbonyl;for alkylaminocarbonyl: methylaminocarbonyl or dimethylaminocarbonyl;for alkoxycarbonylamino: methox