A compound of formula (Ic): ** Formula ** wherein: R1 is selected from the group consisting of: C1-C14 alkyl, C1-C14 arylalkyl, aryl and CO2H； R2 is L where L is - (CR20R21) m- (CR22R23) n- (CR24R25) or-NR26R27； wherein each of R20, R21, R22, R23, R24 and R25 is independently selected from the group consisting of H and C1-C14 alkyl； or R20 and R21 when taken together can form a group of formula>； = O or>； = S, and / or R22 and R23 when taken together can form a group of formula>； = O or>； = S, and / or R24 and R25 when taken together can form a group of formula>； = O or>； = S； each of R26 and R27 is independently selected from the group consisting of: H, C1-C14 alkyl, C2-C14 heteroalkyl, C5-C10 cycloalkyl, optionally substituted aryl, C1-C14 arylalkyl, C5-C10 cycloalkyl C4 and G, or R26 and R27 when taken together with the nitrogen atom to which they are attached form a heterocycloalkyl that may be optionally substituted； wherein the optional substituents on the heterocycloalkyl are selected from the group consisting of H, methyl, ethyl and benzyl. wherein the optional substituents on the aryl are selected from the group consisting of H, methoxy, methylenedioxy, and piperidinyl. m, n and o are each integers that are independently selected from the group consisting of 0, 1, 2, 3 and 4； G is a group of the formula: -L3W3 wherein L3 is C1-C5 alkylene； W3 is selected from the group consisting of -OR12, -N (R12) 2, and -C (O) N (R12) 2. R12 is selected from the group consisting of H, -CN, C1-C14 alkyl, C2-C14 alkynyl, C1-C14 haloalkyl, C2-C14 heteroalkyl, hydroxy, and C1-C14 hydroxyalkyl. or one of its pharmaceutically acceptable salts.Un compuesto de fórmula (Ic): **Fórmula** en donde: R1 se selecciona del grupo que consiste en: alquilo C1-C14, arilalquilo C1-C14, arilo y CO2H； R2 es L donde L es -(CR20R21)m-(CR22R23)n-(CR24R25)o-NR26R27； en donde cada uno de R20, R21, R22, R23, R24 y R25 se selecciona independientemente del grupo que consiste en H y alquilo
