Tetrahydrofuran substituted adenosine A1 receptor agonists, pharmaceuticals thereof, and their use as medicaments

A compound of formula (I), wherein: R2 is C1-3alkyl, halogen or hydrogen. R3 is C1-6 Alkyl. R1 is a group selected from: i) Optionally substituted -(alk)n-(C3-7)cycloalkyl, including bridged cycloalkyl wherein (alk) represents C1-3 alkylene and n is 0 or 1. ii) Optionally substituted aliphatic heterocyclic of 4 to 6 ring members containing at least one heteroatom selected from O, N or S. iii) Optionally substituted alkyl, the alkyl group optionally containing one of more O, S(=O)n (where n is 0, 1 or 2) or N groups substituted within the alkyl chain. iv) A fused bicyclic ring system (II), wherein B is a 5 or 6 membered heterocyclic aromatic ring containing 1 or more O, N or S atoms, wherein the bicyclic ring system is attached to the nitrogen atom of formula (I) via a ring atom or ring A and wherein ring B is optionally substituted by -CO2(C1-3alkyl). v) Optionally substituted phenyl. With the proviso that, when R3 is C1-6alkyl and R2 is C1-3alkyl, R1 cannot represent phenyl substituted by one or more of halogen, C1-3alkyl, trifluoromethyl, nitro, cyano, -CO2Rc, -CONRcRd, -CORc, -SORc, -SO2Rc, -SO3H, -SO2NRcRd, -ORc, -NHSO2Rc, -NHCORc or -NRcRd. Also described is a pharmaceutical composition comprising a compound of formula (I) together with a pharmaceutical carrier and/or excipient. The compounds of formula (I) are useful for the treatment of a patient suffering from or susceptible to ischemic heart disease, peripheral vascular disease or stroke, or which patient is suffering pain, a CNS disorder or sleep apnoea. The compounds of formula (I) are useful for the treatment of a patient suffering from a condition where there is advantage in decreasing plasma free fatty acid concentration, or reducing heart rate.