A compound of formula: wherein R 1 is 5- or 6-membered heteroaryl wherein the heteroaryl contains from one to three heteroatoms independently selected from oxygen and nitrogen and is substituted by one or two substituents independently selected from halo, cyano, C 1-6 alkoxy, -NHSO 2 C 1-6 alkyl, -XR 3 and C 1-6 alkyl wherein the C 1-6 alkyl is optionally substituted by halo; R 2 is -OR 4, -CONHR 5, or 5- or 6-membered heteroaryl wherein the heteroaryl contains from one to three heteroatoms independently selected from oxygen and nitrogen and is substituted by one or two substituents independently selected from halo, cyano, C 1-6 alkoxy, -NHSO 2 C 1-6 alkyl, -CONR 6 R 7, -YR 8 and C 1-6 alkyl wherein the C 1-6 alkyl is optionally substituted by one or two substituents independently selected from hydroxy and -NR 9 R 10; R 3 is 5- or 6-membered heterocyclyl wherein the heterocyclyl contains one or two heteroatoms independently selected from oxygen and nitrogen and is optionally substituted by from one to three substituents independently selected from C 1-6 alkyl; R 4 is C 1-6 alkyl optionally substituted by C 3-6 cycloalkyl or 5- or 6-membered heterocyclyl containing one or two heteroatoms selected from oxygen and nitrogen wherein the C 3-6 cycloalkyl is optionally substituted by -NHCO 2 C 1-6 alkyl and the heterocyclyl is optionally substituted by from one to three substituents independently selected from halo, -COC 1-6 alkyl, -CO 2 C 1-6 alkyl and C 1-6 alkyl optionally substituted by -OR 11; R 5 is hydrogen or C 1-6 alkyl optionally substituted by 6-membered heterocyclyl wherein the heterocyclyl contains an oxygen atom or a nitrogen atom and is optionally substituted by C 1-6 alkyl; R 6 and R 7, together with the nitrogen atom to which they are attached, are linked to form a 5- or 6-membered heterocyclyl wherein the heterocyclyl optionally contains an oxygen atom or a further nitrogen atom and is optionally substituted by C 1-6 alkyl; R 8 is 5- to 9-membered heterocyclyl wherein the heterocyclyl contains one or two heteroatoms independently selected from oxygen and nitrogen and is substituted by from one to three substituents independently selected from oxo, hydroxy, halo, -COC 1-6 alkyl and C 1-6 alkyl optionally substituted by - OR 12; R 9, R 10, R 11 and R 12 are each independently hydrogen or C 1-6 alkyl; X and Y are each independently -CH 2 - or -CH(CH 3)-; or a salt thereof. R 1 is 5- or 6-membered heteroaryl wherein the heteroaryl contains from one to three heteroatoms independently selected from oxygen and nitrogen and is substituted by one or two substituents independently selected from halo, cyano, C 1-6 alkoxy, -NHSO 2 C 1-6 alkyl, -XR 3 and C 1-6 alkyl wherein the C 1-6 alkyl is optionally substituted by halo; R 2 is -OR 4, -CONHR 5, or 5- or 6-membered heteroaryl wherein the heteroaryl contains from one to three heteroatoms independently selected from oxygen and nitrogen and is substituted by one or two substituents independently selected from halo, cyano, C 1-6 alkoxy, -NHSO 2 C 1-6 alkyl, -CONR 6 R 7, -YR 8 and C 1-6 alkyl wherein the C 1-6 alkyl is optionally substituted by one or two substituents independently selected from hydroxy and -NR 9 R 10; R 3 is 5- or 6-membered heterocyclyl wherein the heterocyclyl contains one or two heteroatoms independently selected from oxygen and nitrogen and is optionally substituted by from one to three substituents independently selected from C 1-6 alkyl; R 4 is C 1-6 alkyl optionally substituted by C 3-6 cycloalkyl or 5- or 6-membered heterocyclyl containing one or two heteroatoms selected from oxygen and nitrogen wherein the C 3-6 cycloalkyl is optionally substituted by -NHCO 2 C 1-6 alkyl and the heterocyclyl is optionally substituted by from one to three substituents independently selected from halo, -COC 1-6 alkyl, -CO 2 C 1-6 alkyl and C 1-6 alkyl optionally substituted by -OR 11; R 5 is hydrogen or C 1-6 alkyl optionally substituted by 6-membered heterocyclyl wherein the heterocyclyl contains an oxygen atom or a nitrogen atom and is optionally substituted by C 1-6 alkyl; R 6 and R 7, together with the nitrogen atom to which they are attached, are linked to form a 5- or 6-membered heterocyclyl wherein the heterocyclyl optionally contains an oxygen atom or a further nitrogen atom and is optionally substituted by C 1-6 alkyl; R 8 is 5- to 9-membered heterocyclyl wherein the heterocyclyl contains one or two heteroatoms independently selected from oxygen and nitrogen and is substituted by from one to three substituents independently selected from oxo, hydroxy, halo, -COC 1-6 alkyl and C 1-6 alkyl optionally substituted by - OR 12; R 9, R 10, R 11 and R 12 are each independently hydrogen or C 1-6 alkyl; X and Y are each independently -CH 2 - or -CH(CH 3)-;