Pyrazolo[4,3-D]Pyrimidines

A compound of formula (I)

• wherein
• R1 is a cyclic group selected from RA, RB, RC and RD, each of which is optionally substituted with one or more R7 groups;
• R2 is hydrogen or C1-C2 alkyl;
• R3 and R4 are each independently C1-C8 alkyl, C2-C8 alkenyl, C2-C8 alkynyl or C3-C10 cycloalkyl, each of which is optionally substituted with one or more R8 groups, or RE, which is optionally substituted with one or more R9 groups, or hydrogen;
• or —NR3R4 forms RF, which is optionally substituted with one or more R10 groups;
• R5 is —Y—NR15R16;
• R6, which may be attached at N1 or N2, is C1-C6 alkyl, C1-C6 haloalkyl, C2-C6 alkenyl or C2-C6 alkynyl, each of which is optionally substituted by C1-C6 alkoxy, (C3-C6 cycloalkyl)methoxy, C1-C6 haloalkoxy or a cyclic group selected from RJ, RK, RL and RM, or R6 is RN, C3-C7 cycloalkyl or C3-C7 halocycloalkyl, each of which is optionally substituted by C1-C6 alkoxy or C1-C6 haloalkoxy, or R6 is hydrogen;
• R7 is halo, C1-C6 alkyl, C1-C6 haloalkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C10 cycloalkyl, C3-C10 halocycloalkyl, phenyl, OR12, OC(O)R12, NO2, NR12R13, NR12C(O)R13, NR12CO2R14, C(O)R12, CO2R12, CONR12R13 or CN;
• R8 is halo, phenyl, C1-C6 alkoxyphenyl, OR12, OC(O)R12, NO2, NR12R13, NR12C(O)R13, NR12CO2R14, C(O)R12, CO2R12, CONR12R13, CN, C3-C6 cycloalkyl, RG or RH, the last two of which are optionally substituted with one or more R9 groups;
• R9 is C1-C6 alkyl, C1-C6 haloalkyl or CO2R12;
• R10 is halo, C3-C10 cycloalkyl, C3-C10 halocycloalkyl, phenyl, OR12, OC(O)R12, NO2, NR12R13, NR12C(O)R13, NR12CO2R14, C(O)R12, CO2R13, CONR12R13, CN, oxo, C1-C6 alkyl or C1-C6 haloalkyl, the last two of which are optionally substituted by R11;
• R11 is phenyl, NR12R13 or NR12CO2R14;
• R12 and R13 are each independently hydrogen, C1-C6 alkyl or C1-C6 haloalkyl;
• R14 is C1-C6alkyl or C1-C6 haloalkyl;
• R15 is selected from R17, R17C(O) and R18SO2, and
• R16 is selected from hydrogen, C1-C6 alkyl optionally substituted with one or more R19 groups, C1-C6 haloalkyl and C3-C10 cycloalkyl optionally substituted with one or more R20 groups,
• or —NR15R16 constitutes a 3- to 8-membered saturated ring which may optionally include one or more further heteroatoms selected from nitrogen, oxygen and sulphur, and which may optionally be substituted with one or more groups selected from R21, R22 and (C1-C6 alkoxy)C1-C6 alkyl;
• R17 is hydrogen or R18;
• R18 is selected from C1-C6 alkyl optionally substituted with one or more R19 groups, C1-C6 haloalkyl and C3-C10 cycloalkyl optionally substituted with one or more R20 groups;
• R19 is selected from R21, —NR23R24, —CO2R25, —CONR26R27, R28 and phenyl optionally substituted by R29;
• R20 is selected from R21, R22 and oxo;
• R21 is oxo, hydroxy, C1-C6 alkoxy, C1-C6 (haloalkyl)oxy or C3-C7 cycloalkyloxy;
• R22 is C1-C6 alkyl or C1-C6 haloalkyl;
• R23 and R24 are each independently selected from hydrogen and C1-C6 alkyl;
• or —NR23R24 constitutes an azetidine, pyrrolidine, piperidine or morpholine ring;
• R25 is hydrogen or C1-C6 alkyl;
• R26 and R27 are each independently selected from hydrogen and C1-C6 alkyl;
• or —NR26R27 constitutes an azetidine, pyrrolidine, piperidine or morpholine ring;
• R28 is a saturated, unsaturated or aromatic heterocycle with up to 10 ring atoms, at least one of which is selected from nitrogen, oxygen and sulphur;
• R29 is selected from halo, R21 and R22,
• RA and RJ are each independently a C3-C10 cycloalkyl or C3-C10 cycloalkenyl group, each of which may be either monocyclic or, when there are an appropriate number of ring atoms, polycyclic and which may be fused to either
• (a) a monocyclic aromatic ring selected from a benzene ring and a 5- or 6-membered heteroaromatic ring containing up to three heteroatoms selected from nitrogen, oxygen and sulphur, or
• (b) a 5-, 6- or 7-membered heteroalicyclic ring containing up to three heteroatoms selected from nitrogen, oxygen and sulphur;
• RB and RK are each independently a phenyl or naphthyl group, each of which may be fused to
• (a) a C5-C7 cycloalkyl or C5-C7 cycloalkenyl ring,
• (b) a 5-, 6- or 7-membered heteroalicyclic ring containing up to three heteroatoms selected from nitrogen, oxygen and sulphur, or
• (c) a 5- or 6-membered heteroaromatic ring containing up to three heteroatoms selected from nitrogen, oxygen and sulphur;
• RC, RL and RN are each independently a monocyclic or, when there are an appropriate number of ring atoms, polycyclic saturated or partly unsaturated ring system containing between 3 and 10 ring atoms, of which at least one is a heteroatom selected from nitrogen, oxygen and sulphur, which ring may be fused to a C5-C7 cycloalkyl or C5-C7 cycloalkenyl group or a monocyclic aromatic ring selected from a benzene ring and a 5- or 6-membered heteroaromatic ring containing up to three heteroatoms selected from nitrogen, oxygen and sulphur;
• RD and RM are each independently a 5- or 6-membered heteroaromatic ring containing up to three heteroatoms independently selected from nitrogen, oxygen and sulphur, which ring may further be fused to
• (a) a second 5- or 6-membered heteroaromatic ring containing up to three heteroatoms selected from nitrogen, oxygen and sulphur;
• (b) C5-C7 cycloalkyl or C5-C7 cycloalkenyl ring;
• (c) a 5-, 6- or 7-membered heteroalicyclic ring containing up to three heteroatoms selected from nitrogen, oxygen and sulphur;
• or
• (d) a benzene ring;
• RE, RF and RG are each independently a monocyclic or, when there are an appropriate number of ring atoms, polycyclic saturated ring system containing between 3 and 10 ring atoms, of which at least one is a heteroatom selected from nitrogen, oxygen and sulphur;
• RH is a 5- or 6-membered heteroaromatic ring containing up to three heteroatoms independently selected from nitrogen, oxygen and sulphur;
• and
• Y is a covalent bond, C1-C6 alkylenyl or C3-C7 cycloalkyenyl;
• a tautomer thereof or a pharmaceutically acceptable salt, solvate or polymorph of said compound or tautomer.