Quinoline derivatives as ligands NK2 and NK3 receptors.

A compound, or its pharmaceutically acceptable salt or solvate of formula (I): wherein: R is C1-6 alkyl; R1 is hydrogen; R2 is a - (CH2) n-NY1Y2 wherein n is 1 and -NY1Y2 is a group of formula (a): wherein T1 is C1-6 alkyl; R3 is phenyl; and R4 is C1-6 alkyl.