Patent ID: 8586608

Claim:
A compound of formula I wherein: R a is a benzyl or 1-phenylethyl group; R b is bis(2-methoxyethyl)amino, morpholino, N-methyl-N-(tetrahydrofuran-3-yl)amino, N-methyl-N-(tetrahydrofuran-2-ylmethyl)amino, N-methyl-N-(tetrahydrofuran-3-ylmethyl)amino, N-methyl-N-(tetrahydropyran-4-yl)amino, or N-methyl-N-(tetrahydropyran-4-ylmethyl)amino group; and R c is a cyclopropylmethoxy, cyclobutyloxy or cyclopentyloxy group, or a stereoisomer, or physiologically acceptable salt thereof.