A compound of formula (I): ** Formula ** in which R 1 is 9 or 10 membered bicyclic heteroaryl, wherein the 9 or 10 membered bicyclic heteroaryl contains one to three heteroatoms independently selected from oxygen and nitrogen, and is optionally substituted with C1-6 alkyl, C3-6 cycloalkyl, halo, -CN or -NHSO2R5, or pyridinyl optionally substituted with one or two substituents independently selected from C1-6 alkyl, -OR6, halo and -NHSO2R7； X is -CH2NR2R3, C1-6 alkyl, -CH2phenyl, - (CH2) nOR10, -CH2SO2R11 or - (CH2) C3-6 cycloalkyl； R2 and R3, together with the nitrogen atom to which they are attached, bind to form a 6 or 7 membered heterocyclyl or a 9 or 10 membered bicyclic heterocyclyl in which the 6 or 7 membered heterocyclyl or the bicyclic heterocyclyl of 9 or 10 members optionally contains an oxygen atom, a sulfur atom or an additional nitrogen atom and is optionally substituted with one to three substituents independently selected from oxo, C1-6 alkyl, - (CH2) mNR8R9, phenyl optionally substituted with halo, and 6-membered heteroaryl in which the 6-membered heteroaryl contains one or two nitrogen atoms, a 7-membered bridged heterocyclyl in which the 7-membered bridged heterocyclyl optionally contains an additional nitrogen atom and is optionally substituted with one to three substituents independently selected from C1-6 alkyl, or a 10-membered bicyclic spiro heterocyclyl in which the spiro heterocyclyl 10-membered bicyclic optionally contains an oxygen atom, or R2 is hydrogen and R3 is C1-6 alkyl optionally substituted with one or two substituents independently selected from -OR12 and -NR13R14； R4 is hydrogen or methyl； each of R6, R12 and R15 is independently hydrogen or C1-4 alkyl； each of R5 and R7 is independently C1-6 alkyl or phenyl in which the phenyl is optionally substituted with one or two substituents independently selected from halo and -OR15； R8 and R9, together with the nitrogen atom to which they are attached, bind to form a 5- or 6-membered he
