A compound of the formula (IA): ** Formula ** or a pharmaceutically acceptable salt thereof, wherein: R1 is H, COOR ', or an alkyl of 1 to 4 carbon atoms, alkenyl of 2 to 4 atoms of carbon, alkynyl of 2 to 4 carbon atoms, or cycloalkyl of 3 to 6 optionally substituted carbon atoms, wherein each R 'is independently H or alkyl of 1 to 4 carbon atoms； R2 is H or an alkyl of 1 to 4 optionally substituted carbon atoms, with the proviso that R1 and R2 are not both H； or R1 and R2 taken together may optionally form a 3 to 6 membered cycloalkyl ring, or a 3 to 6 membered heterocyclic ring containing N, O or S as a ring member, each of which is optionally substituted； Y is NR6, where R6 is H or alkyl of 1 to 4 optionally substituted carbon atoms； or R6 and L taken together with the nitrogen atom (N) with which they are attached, form a 5- to 7-membered heterocyclic group that optionally contains an additional heteroatom selected from N, O and S as a ring member, and is substituted with -L2-Z and up to two groups selected from alkyl of 1 to 4 carbon atoms, hydroxyl, alkoxy of 1 to 4 carbon atoms, amino, alkyl of 1 to 4 carbon atoms-amino and di - (alkyl of 1 to 4 carbon atoms) -amino； L is a bond or a cycloalkyl of 3 to 7 carbon atoms, heteroaryl of 5 to 6 carbon atoms, or heterocyclic ring of 4 to 7 optionally substituted carbon atoms； L2 is a divalent linker selected from a bond, - (CR3R4) 1-2-, -SO2-, and -SO2-CR3R4-； each R3 and R4 is independently H or alkyl of 1 to 4 carbon atoms optionally substituted with up to three groups, or R3 and R4 taken together can form a cycloalkyl of 3 to 5 carbon atoms optionally substituted with up to three groups, wherein the Up to three groups that replace R3, R4, or R3 and R4 taken together to form a cycloalkyl of 3 to 5 carbon atoms, are selected from Me, Et, CF3, F, Cl, hydroxyl, methoxy, oxo, amino, methyl amino and dimethyl amino； Z is optionally substituted alkyl of 1 to 6 carbon atoms, or a 5-10 membered aryl, aryl-alkyl (of 1-4 c
