om to which they are attached, form a group selected from morpholin-4-yl, thiomorpholin-4-yl, piperidin-1-yl and pyrrolidin-1-yl; each of R12 and R13 is independently hydrogen or C1-4 alkyl; n is 2, 3, 4 or 5; p is 2 or 3; Z is a methyl group or a halogen atom; and Y is a methylene group or an oxygen atom.