A compound of formula I wherein X is O or NH; R 1 is phenyl or pyridine-2-yl, wherein the rings may be optionally substituted with one, two or three halo; R 2 is hydrogen or C 1-4 alkyl; R 3 and R 4 each are independently H, -C -R a, wherein R a is hydroxy, C 1-7 alkoxy, C 1-7 alkyl, phenoxy or phenyl, -C -NR b R c, wherein R b and R c are each independently H, C 1-7 alkyl, optionally substituted with one or more halo, hydroxy, or cyano, -(CH 2) z -C 3-7 cycloalkyl, optionally substituted by one or more B, and z is 0, 1, 2, 3 or 4, -(CH 2) y -heterocyclyl, wherein y is 0, 1, 2, 3 or 4, and wherein heterocyclyl is optionally substituted by one or more A R b and R c together with the nitrogen to which they are bound form a heterocyclyl moiety, optionally substituted with one or more A, or or R 3 and R 4 together form an annelated benzo ring, the benzo ring is optionally substituted by one or more E, A is hydroxy, oxo, C 1-7 alkyl, C 1-7 alkoxy, C 1-7 haloalkyl, C 1-7 hydroxyalkyl, halo, or CN, B is halo, hydroxy, CN, C 1-4 alkyl, or C 1-4 haloalkyl, E is halo, CN, NO 2, hydroxy, C 1-7 alkyl, C 1-7 alkoxy, C 1-7 haloalkyl, C 1-7 hydroxyalkyl, C 1-7 cyanoalkyl, C 1-7 haloalkoxy, or C 3-7 cycloalkyl, or a pharmaceutically acceptable salt thereof; wherein the term "heterocyclyl" or "heterocyclyl moiety" refers to a monovalent saturated or partially saturated 3- to 7-membered monocyclic or 9- to 10-membered bicyclic ring system wherein one, two, three or four ring carbon atoms have been replaced by N, O or S, and with the attachment point on the saturated or partially unsaturated ring of said ring system. X is O or NH; R 1 is phenyl or pyridine-2-yl, wherein the rings may be optionally substituted with one, two or three halo; R 2 is hydrogen or C 1-4 alkyl; R 3 and R 4 each are independently H, -C -R a, wherein R a is hydroxy, C 1-7 alkoxy, C 1-7 alkyl, phenoxy or phenyl, -C -NR b R c, wherein R b and R c are each independently H, C 1-7 alkyl, optionally substituted with one or more halo, hydroxy, or cyano, -(CH 2) z -C 3-7 cycloalkyl, optionally substituted by one or more B, and z is 0, 1, 2, 3 or 4, -(CH 2) y -heterocyclyl, wherein y is 0, 1, 2, 3 or 4, and wherein heterocyclyl is optionally substituted by one or more A R b and R c together with the nitrogen to which they are bound form a heterocyclyl moiety, optionally substituted with one or more A, or or R 3 and R 4 together form an annelated benzo ring, the benzo ring is optionally substituted by one or more E, H, -C -R a, wherein R a is hydroxy, C 1-7 alkoxy, C 1-7 alkyl, phenoxy or phenyl, -C -NR b R c, wherein R b and R c are each independently H, C 1-7 alkyl, optionally substituted with one or more halo, hydroxy, or cyano, -(CH 2) z -C 3-7 cycloalkyl, optionally substituted by one or more B, and z is 0, 1, 2, 3 or 4, -(CH 2) y -heterocyclyl, wherein y is 0, 1, 2, 3 or 4, and wherein heterocyclyl is optionally substituted by one or more A R b and R c together with the nitrogen to which they are bound form a heterocyclyl moiety, optionally substituted with one or more A, or H, C 1-7 alkyl, optionally substituted with one or more halo, hydroxy, or cyano, -(CH 2) z -C 3-7 cycloalkyl, optionally substituted by one or more B, and z is 0, 1, 2, 3 or 4, -(CH 2) y -heterocyclyl, wherein y is 0, 1, 2, 3 or 4, and wherein heterocyclyl is optionally substituted by one or more A R b and R c together with the nitrogen to which they are bound form a heterocyclyl moiety, optionally substituted with one or more A, or or R 3 and R 4 together form an annelated benzo ring, the benzo ring is optionally substituted by one or more E, A is hydroxy, oxo, C 1-7 alkyl, C 1-7 alkoxy, C 1-7 haloalkyl, C 1-7 hydroxyalkyl, halo, or CN, B is halo, hydroxy, CN, C 1-4 alkyl, or C 1-4 haloalkyl, E is halo, CN, NO 2, hydroxy, C 1-7 alkyl, C 1-7 alkoxy, C 1-7 haloalkyl, C 1-7 hydroxyalkyl, C 1-7 cyanoalkyl, C 1-7 haloalkoxy, or C 3-7 cycloalkyl,