Patent ID: 8846701

Claim:
A compound of formula (I): wherein: R1 is an ortho-substituted-aryl group or a heterocyclyl or C 3 -C 7 cycloalkyl group; R2 is hydrogen atom or a straight or branched C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 7 cycloalkyl or heterocyclyl group; R3 is aryl; R4 is hydrogen atom, hydroxyl or C 1 -C 6 alkyl group, which group may be optionally cyclized together with one of the atom of the group which R3 may represent so as to form a fused C 4 -C 7 cyclic group; R5 and R6: are each independently hydrogen atom, C 1 -C 6 alkyl, or are optionally cyclized together with the carbon atom to which they are bonded so as to form a C 3 -C 7 cycloalkyl group; wherein the groups ortho-substituted-aryl, aryl, heterocyclyl, C 3 -C 7 cycloalkyl, C 4 -C 7 cycloalkyl, C 1 -C 6 alkyl, C 2 -C 6 alkenyl and C 2 -C 6 alkynyl may be optionally (further) substituted; and the pharmaceutically acceptable salts thereof.