A compound of formula (I) wherein R is H or selected from the group consisting of (C 1 -C 4 )alkyl, (C 1 -C 4 )haloalkyl and 5-6 membered heteroaryl, wherein each of said heteroaryl may be optionally substituted by one or more group selected from (C 1 -C 4 )alkyl, halo, (C 1 -C 4 )haloalkyl; R 1 is H or (C 1 -C 4 )alkyl; R 2 is H or selected from the group consisting of (C 1 -C 4 )alkyl, halo, (C 1 -C 4 )haloalkyl and (C 3 -C 8 )cycloalkyl; R 3 is H or (C 1 -C 4 )alkyl; A is selected from the group consisting of 5-6 membered heteroaryl wherein each of said heteroaryl may be optionally substituted by one or more group selected from (C 1 -C 4 )alkyl, -C(O)R 1 , -C(O)OR 1 , -C(O)R 1 , (C 1 -C 4 )haloalkyl, halo,-NR A C(O)R 1 , -NR A C(O)OR 1 , -NR A C(O)-(C 1 -C 4 )alkylene-OR 1 , -NR A C(O)R C ,-NR A C(O)NR A R B , -N(C 1 -C 4 )alkylene-NR A R B , heteroaryl optionally substituted by one or more (C 1 -C 4 )alkyl and (C 1 -C 4 )haloalkyl, R C is selected from the group consisting of heteroaryl, aryl, (C 3 -C 8 ) cycloalkyl and (C 4 -C 8 ) heterocycloalkyl wherein said heteroaryl, aryl, heterocycloalkyl and cycloalkyl may be optionally substituted by one or more (C 1 -C 4 )alkyl and-C(O)OR 1 ; R A and R B are at each occurrence independently H or selected from the group consisting of (C 1 -C 4 )alkyl, (C 3 -C 8 )cycloalkyl, (C 1 -C 6 )haloalkyl and halo, or R A and R B may form together with the nitrogen atom to which they are attached a 4-6 membered saturated heterocyclic ring system optionally containing a further heteroatom selected from N, S and O, said heterocyclic ring system may be optionally substituted by one or more groups selected from (C 1 -C 4 )alkyl, (C 1 -C 4 ) haloalkyl and halo. R is H or selected from the group consisting of (C 1 -C 4 )alkyl, (C 1 -C 4 )haloalkyl and 5-6 membered heteroaryl, wherein each of said heteroaryl may be optionally substituted by one or more group selected from (C 1 -C 4 )alkyl, halo, (C 1 -C 4 )haloalkyl; R 1 is H or (C 1 -C 4 )alkyl; R 2 is H or selected from the group consisting of (C 1 -C 4 )alkyl, halo, (C 1 -C 4 )haloalkyl and (C 3 -C 8 )cycloalkyl; R 3 is H or (C 1 -C 4 )alkyl; A is selected from the group consisting of 5-6 membered heteroaryl wherein each of said heteroaryl may be optionally substituted by one or more group selected from (C 1 -C 4 )alkyl, -C(O)R 1 , -C(O)OR 1 , -C(O)R 1 , (C 1 -C 4 )haloalkyl, halo,-NR A C(O)R 1 , -NR A C(O)OR 1 , -NR A C(O)-(C 1 -C 4 )alkylene-OR 1 , -NR A C(O)R C ,-NR A C(O)NR A R B , -N(C 1 -C 4 )alkylene-NR A R B , heteroaryl optionally substituted by one or more (C 1 -C 4 )alkyl and (C 1 -C 4 )haloalkyl, R C is selected from the group consisting of heteroaryl, aryl, (C 3 -C 8 ) cycloalkyl and (C 4 -C 8 ) heterocycloalkyl wherein said heteroaryl, aryl, heterocycloalkyl and cycloalkyl may be optionally substituted by one or more (C 1 -C 4 )alkyl and-C(O)OR 1 ; R A and R B are at each occurrence independently H or selected from the group consisting of (C 1 -C 4 )alkyl, (C 3 -C 8 )cycloalkyl, (C 1 -C 6 )haloalkyl and halo, or R A and R B may form together with the nitrogen atom to which they are attached a 4-6 membered saturated heterocyclic ring system optionally containing a further heteroatom selected from N, S and O, said heterocyclic ring system may be optionally substituted by one or more groups selected from (C 1 -C 4 )alkyl, (C 1 -C 4 ) haloalkyl and halo. <EOS>