Patent ID: 7956053

Claim:
A compound of formula wherein R 1 represents hydrogen, lower alkyl, lower alkoxy-lower alkyl, acyloxy-lower alkyl, carboxy-lower alkyl, lower alkoxycarbonyl-lower alkyl, or phenyl-lower alkyl; R 2 represents lower alkyl substituted by one or more identical or different radicals R 3 , cycloalkyl, benocycloalkyl, heterocyclyl, or a mono- or bicyclic heteroaryl group comprising zero, one, two or three ring nitrogen atoms and zero or one oxygen atom and zero or one sulfur atom, which groups in each case are unsubstituted or mono- or polysubstituted; and R 3 represents hydroxy, lower alkoxy, acyloxy, carboxy, lower alkoxycarbonyl, carbamoyl, N-mono- or N,N-disubstituted carbamoyl, phenylamino, N-lower alkyl-N-phenylamino, cycloalkyl, heterocyclyl, an aryl group, or a mono- or bicyclic heteroaryl group comprising zero, one, two or three ring nitrogen atoms and zero or one oxygen atom and zero or one sulfur atom, which groups in each case are unsubstituted or mono- or polysubstituted; R 4 represents hydrogen, lower alkyl, or halogen; or a N-oxide or a pharmaceutically acceptable salt thereof.