Compounds

A compound of formula ##STR1##

or a pharmaceutically acceptable salt thereof, wherein R is C(O)Ar¹, C(R⁴)(R⁵)Ar¹ or Ar³; R³ represents a group XR¹⁰ or Ar²; X represents a bond or a group NR¹¹; and R¹⁰ represents C_1-6 alkyl, C_2-6 alkenyl or C_2-6 alkynyl, each of which may be optionally substituted by one or more substituents independently selected from carboxyl, hydroxyl, C(O)R¹², C_3-6 cycloalkyl, morpholinyl, NR¹³R¹⁴, SR¹⁵, OR¹⁶, phenyl and halophenyl, or R¹⁰ represents a C_3-6 cycloalkylcarbonyl, C(O)CH₂CN, halophenylcarbonyl or trifluoromethylcarbonyl group. The compounds or compositions thereof are useful in the treatment or prophylaxis of autoimmune, inflammatory, proliferative and hyperproliferative diseases.