1. The compound of formula I:! ! or a pharmaceutically acceptable salt of said compound, wherein! R1 and R1 'independently represent hydrogen or a C1-6 aliphatic group which may contain substituents, or R1 and R1' together form a 3-7 membered carbocyclic ring which may have substituents； ! R2a is —OH or —NHSO2R2； ! R2 is —N (R) 2 or optionally a substituent group selected from the following: C3-7 cycloalkyl, bicyclic bridged, 6-10 membered aryl, 5-10 membered heteroaryl containing 1-4 heteroatoms that are independently selected from nitrogen, oxygen or sulfur, or a 4-7 membered heterocycle containing 1-2 heteroatoms that are independently selected from nitrogen, oxygen or sulfur； ! each R independently represents hydrogen, possibly containing substituents C1-6 aliphatic group, or! two R together with the nitrogen atom to which they are attached form a 4-7 membered heterocyclic ring containing 1-2 heteroatoms that are independently selected from nitrogen, oxygen or sulfur； ! R3 is -L-Y where! L is a covalent bond or a divalent, saturated or unsaturated, straight or branched C1-8 hydrocarbon chain, where one or two methylene units in L can be independently replaced by cyclopropylene, -NR-, -N (R) C (O) -, -C (O) N (R) -, -N (R) SO2-, -SO2N (R) -, -O-, -C (O) -,! -OC (O) -, -C (O) O-, -S-, -SO-, -SO2-, -C (= S) -, -C (= NR) -, -N = N- or - C (= N2) -； ! Y is hydrogen； A C1-6 aliphatic group which may contain as substituents an oxo group, halogen, NO2, or CN； or a 3-10 membered monocyclic or bicyclic, saturated or partially unsaturated, or aryl ring containing 0-3 heteroatoms that1. Соединение формулы I: ! ! или фармацевтически приемлемая соль указанного соединения, где ! R1 и R1' независимо представляют собой водород или C1-6 алифатическую группу, которая может содержать заместители, или R1 и R1' совместно образуют 3-7-членное карбоциклическое кольцо, которое может иметь заместители； ! R2a представляет собой -ОН или -NHSO2R2； ! R2 представляет собой -N(R)2 или
