Fluorophenyl beta-hydroxyethylamines and their use in the treatment of hyperglycaemia

A compound of formula IB

• or a pharmaceutically acceptable salt thereof, wherein:
• R1 represents C4-12 alkyl optionally substituted by one or more halo;
• R2 and R3 each independently represent H or C1-3 alkyl optionally substituted by one or more halo;
• or R2 and R3 may be linked together to form, together with the carbon atom to which they are attached, a 3- to 6-membered ring, which ring optionally is substituted by one or more groups independently selected from halo and C1 alkyl optionally substituted by one or more halo;
• each X independently represents Cl, Br, Ra, —CN, —N3, —N(Rb)Rc, —NO2, —ONO2, —ORd, —S(O)pRe or —S(O)qN(Rf)Rg;
• Ra represents C1-6 alkyl optionally substituted by one or more groups independently selected from G;
• each Rb, Rc, Rd, Re, Rf and Rg independently represents H or C1-6 alkyl optionally substituted by one or more groups independently selected from G;
• or alternatively any of Rb and Rc and/or Rf and Rg may be linked together to form, together with the nitrogen atom to which they are attached, a 4- to 6-membered ring, which ring optionally contains one further heteroatom and which ring optionally is substituted by one or more groups independently selected from halo, C1-3 alkyl optionally substituted by one or more halo, and =0;
• G represents halo, —CN, —N(Ra1)Rb1;
• —ORc1;
• —S(O)pRd1;
• —S(O)qN(Re1)Rf1 or ═O;
• each Ra1, Rb1, Rc1, Rd1, Re1 and Rf1 independently represents H or C1-6 alkyl optionally substituted by one or more halo;
• or alternatively any of Ra1 and Rb1 and/or Re1 and Rf1 may be linked together to form, together with the nitrogen atom to which they are attached, a 4- to 6-membered ring, which ring optionally contains one further heteroatom and which ring optionally is substituted by one or more groups independently selected from halo, C1-3 alkyl optionally substituted by one or more halo, and ═O;
• m represents 2;
• n represents 0 to 4;
• with the proviso that the sum of m and n is equal to, or less than, 5;
• each p independently represents 0, 1 or 2;
• and
• each q independently represents 1 or 2,
• wherein alkyl groups may be straight-chain or, when there is a sufficient number of carbon atoms, be branched-chain, and/or cyclic or part cyclic.