| abstract |
1. The compound of formula I! ! or its pharmaceutically acceptable salt, where! X represents O, S, NR, C (O) or C (R) 2; ! ring A is a phenyl or 5-7 membered heteroaryl ring, wherein ring A is optionally substituted with y substituents R5; ! R1 and R2, each independently, is hydrogen or a C1-6 aliphatic group, where up to two carbon atoms not bonded to the nitrogen atom are optionally replaced with O, S, NR or C (O); ! x is 0-4; ! y is 0-4; ! z is 0-4; ! each of R3, R4 and R5 independently represents Q-Rx; ! Q is a bond or a C1-6 aliphatic chain, where up to two, non-adjacent methylene units, Q is optionally replaced by CO, CO2, COCO, CONR, OCONR, NRNR, NRNRCO, NRCO, NRCO2, NRCONR, SO, SO2, NRSO2, SO2NR, NRSO2NR, O, S or NR; ! each Rx is independently selected from R ', halogen, NO2, CN, OR', SR ', N (R') 2, NR'C (O) R ', NR'C (O) N (R') 2, NR 'CO2R, C (O) R', CO2R ', OC (O) R', C (O) N (R ') 2, OC (O) N (R') 2, SOR ', SO2R', SO2N ( R ') 2, NR'SO2R', NR'SO2N (R ') 2, C (O) C (O) R' or C (O) CH2C (O) R '; ! each R is independently selected from hydrogen or optionally substituted with a C1-6 aliphatic group; and! each R ′ is independently selected from hydrogen or an optionally substituted group selected from a C1-8 aliphatic group, a C6-10 aryl, heteroaryl ring having 5-10 atoms in the ring, or a heterocyclyl ring having 3-10 atoms in the ring, or R and R ', taken together with the atom (s) with which they are bonded, or two R', taken together with the atom (s), with which they are bonded, form a 5-8 membered cycloalkyl, heterocyclyl, aryl or heteroaryl ring having 0 -3 heteroatoms independently selected from nitrogen, oxygen or sulfur, provided that! (i) if R2 is hydrogen, X is O, y is 1, and R5 is OMe, then R3 cannot be NO2,! (ii) if R2 is hydrogen or ethyl, X |