METHOD OF TREATMENT USING SUBSTITUTED PYRAZOLO[1,5-a]PYRIMIDINE COMPOUNDS

A method for treating pain, cancer, inflammation, neurodegenerative disease or Typanosoma cruzi infection in a mammal, which comprises administering to said mammal in need thereof a therapeutically effective amount of a compound of Formula I

• or a pharmaceutically acceptable salt thereof, wherein:
• R1 is H or (1-6C alkyl);
• R2 is NRbRc, (1-4C)alkyl, (1-4C)fluoroalkyl, CF3, (1-4C)hydroxyalkyl, -(1-4C alkyl)hetAr1, -(1-4C alkyl)NH2, -(1-4C alkyl)NH(1-4C alkyl), -(1-4C alkyl)N(1-4C alkyl)2, hetAr2, hetCyc1, hetCyc2, phenyl which is optionally substituted with NHSO2(1-4C alkyl), or (3-6C)cycloalkyl which is optionally substituted with (1-4C alkyl), CN, OH, OMe, NH2, NHMe, N(CH3)2, F, CF3, CO2(1-4C alkyl), CO2H, C(═O)NReRf or C(═O)ORg;
• Rb is H or (1-6C alkyl);
• Rc is H, (1-4C)alkyl, (1-4C)hydroxyalkyl, hetAr3, or phenyl, wherein said phenyl is optionally substituted with one or more substituents independently selected from halogen, CN, CF3 and —O(1-4C alkyl),
• or NRbRc forms a 4 membered heterocyclic ring having a ring nitrogen atom, wherein said heterocyclic ring is optionally substituted with one or more substituents independently selected from halogen, OH, (1-4C alkyl), (1-4 C)alkoxy, —OC(═O)(1-4C alkyl), NH2, —NHC(═O)O(1-4C alkyl) and (1-4C)hydroxyalkyl,
• or NRbRc forms a 5-6 membered heterocyclic ring having a ring heteroatom which is nitrogen and optionally having a second ring heteroatom or group selected from N, O and SO2, wherein the heterocyclic ring is optionally substituted with one or more substituents independently selected from OH, halogen, CF3, (1-4C)alkyl, CO2(1-4C alkyl), CO2H, NH2, NHC(═O)O(1-4C alkyl) and oxo,
• or NRbRc forms a 7-8 membered bridged heterocyclic ring having a ring nitrogen atom and optionally having a second ring heteroatom selected from N and O, wherein said ring is optionally substituted with CO2(1-4C alkyl);
• hetAr1 is a 5-membered heteroaryl ring having 1-3 ring nitrogen atoms;
• hetAr2 is 5-6 membered heteroaryl ring having at least one nitrogen ring atom and optionally having a second ring heteroatom independently selected from N and S, wherein said heteroaryl ring is optionally substituted with one or more substituents independently selected from (1-4C alkyl), halogen, -(1-4 C)alkoxy and NH(1-4C alkyl);
• hetCyc1 is a carbon-linked 4-6 membered azacyclic ring optionally substituted with one or more substituents independently selected from (1-4C alkyl), and CO2(1-4C alkyl);
• hetCyc2 is a pyridinone or pyridazinone ring which is optionally substituted with a substituent selected from (1-4C)alkyl;
• hetAr3 is a 5-6 membered heteroaryl ring having 1-2 ring heteroatoms independently selected from N and O and optionally substituted with one or more substituents independently selected from (1-4C)alkyl;
• Re is H or (1-4C)alkyl;
• Rf is H, (1-4C)alkyl, or (3-6C)cycloalkyl;
• or NReRf forms a 4-6-membered azacyclic ring optionally having an additional ring heteroatom selected from N and O, wherein the azacyclic ring is optionally substituted with OH;
• Rg is H or (1-6C)alkyl;
• Y is (i) phenyl optionally substituted with one or more substituents independently selected from halogen, (1-4C)alkoxy, CF3 and CHF2, or (ii) a 5-6 membered heteroaryl ring having a ring heteroatom selected from N and S, wherein said heteroaryl ring is optionally substituted with one or more halogen atoms;
• X is null, —CH2—, —CH2CH2—, —CH2O—, or —CH2NRd—;
• Rd is H or (1-4C alkyl);
• R3 is H or (1-4C alkyl);
• each R4 is independently selected from halogen, (1-4C)alkyl, OH, (1-4 C)alkoxy, NH2, NH(1-4C alkyl) and CH2OH;
• and
• n is 0, 1, 2, 3, 4, 5 or 6.