Pyrazolo[1,5-A]pyrimidines as antiviral agents

A compound of formula I:

• or a salt or ester, thereof;
• wherein:
• A is —(C(R4)2)n— wherein any one C(R4)2 of said —(C(R4)2)n— may be optionally replaced with —O—, —S—, —S(O)p—, NH or NRa;
• n is 3, 4, 5 or 6;
• each p is 1 or 2;
• Ar is a C2-C20 heterocyclyl group or a C6-C20 aryl group, wherein the C2-C20 heterocyclyl group or the C6-C20 aryl group is optionally substituted with 1, 2, 3, 4 or 5 R6;
• each R3, R4 or R6 is independently H, oxo, OR11, NR11R12, NR11C(O)R11, NR11C(O)OR11, NR11C(═O)NR11R12, N3, CN, NO2, SR11, S(O)pRa, NR11S(O)pRa, —C(═O)R11, —C(═O)OR11, —C(═O)NR11R12, —C(═O)SR11, —S(O)p(OR11), —SO2NR11R12, —NR11S(O)p(OR11), —NR11SOpNR11R12, NR11C(═NR11)NR11R12, halogen, (C1-C8)alkyl, (C2-C8)alkenyl, (C2-C8)alkynyl, aryl(C1-C8)alkyl, C6-C20 aryl, C2-C20 heterocyclyl, (C3-C7)cycloalkyl or (C4-C8)carbocyclylalkyl;
• or two R4 on adjacent carbon atoms, when taken together, may optionally form a double bond between the two carbons to which they are attached or may form a (C3-C7)cycloalkyl ring wherein one carbon atom of said (C3-C7)cycloalkyl ring may be optionally replaced by —O—, —S—, —S(O)p—, —NH— or —NRa—;
• or four R4 on adjacent carbon atoms, when taken together, may optionally form an optionally substituted C6 aryl ring;
• or two R4 on the same carbon atom, when taken together, may optionally form a (C3-C7)cycloalkyl ring wherein one carbon atom of said (C3-C7)cycloalkyl ring may be optionally replaced by —O—, —S—, —S(O)p—, —NH— or —NRa—;
• or two R6 on adjacent carbon atoms, when taken together, may optionally form a (C3-C7)cycloalkyl ring wherein one carbon atom of said (C3-C7)cycloalkyl ring may be optionally replaced by —O—, —S—, —S(O)p—, —NH— or —NRa—;
• each Ra is independently (C1-C8)alkyl, (C1-C8)haloalkyl, (C2-C8)alkenyl, (C2-C8)alkynyl, aryl(C1-C8)alkyl, C6-C20 aryl, C2-C20 heterocyclyl, (C3-C7)cycloalkyl or (C4-C8)carbocyclylalkyl wherein any (C1-C8)alkyl, (C1-C8)haloalkyl, (C2-C8)alkenyl or (C2-C8)alkynyl of Ra is optionally substituted with one or more OH, NH2, CO2H, C2-C20 heterocyclyl, and wherein any aryl(C1-C8)alkyl, C6-C20 aryl, C2-C20 heterocyclyl, (C3-C7)cycloalkyl or (C4-C8)carbocyclylalkyl of Ra is optionally substituted with one or more OH, NH2, CO2H, C2-C20 heterocyclyl or (C1-C8)alkyl;
• each R11 or R12 is independently H, (C1-C8)alkyl, (C2-C8)alkenyl, (C2-C8)alkynyl, aryl(C1-C8)alkyl, C6-C20 aryl, C2-C20 heterocyclyl, (C3-C7)cycloalkyl, (C4-C8)carbocyclylalkyl, —C(═O)Ra, —S(O)pRa or aryl(C1-C8)alkyl;
• or R11 and R12 taken together with a nitrogen to which they are both attached form a 3 to 7 membered heterocyclic ring wherein any one carbon atom of said heterocyclic ring can optionally be replaced with —O—, —S—, —S(O)p—, —NH—, —NRa— or —C(O)—;
• and
• wherein each (C1-C8)alkyl, (C2-C8)alkenyl, (C2-C8)alkynyl, aryl(C1-C8)alkyl, C6-C20 aryl, C2-C20 heterocyclyl, (C3-C7)cycloalkyl or (C4-C8)carbocyclylalkyl of each R6, R11 or R12 is, independently, optionally substituted with one or more oxo, halogen, hydroxy, NH2, CN, N3, N(Ra)2, NHRa, SH, SRa, S(O)pRa, ORa, (C1-C8)alkyl, (C1-C8)haloalkyl, —C(O)Ra, —C(O)H, —C(═O)ORa, —C(═O)OH, —C(═O)N(Ra)2, —C(═O)NHRa, —C(═O)NH2, NHS(O)pRa, NRaS(O)pRa, NHC(O)Ra, NRaC(O)Ra, NHC(O)ORa, NRaC(O)ORa, NRaC(O)NHRa, NRaC(O)N(Ra)2, NRaC(O)NH2, NHC(O)NHRa, NHC(O)N(Ra)2, NHC(O)NH2, ═NH, ═NOH, ═NORa, NRaS(O)pNHRa, NRaS(O)pN(Ra)2, NRaS(O)pNH2, NHS(O)pNHRa, NHS(O)pN(Ra)2, NHS(O)pNH2, —OC(═O)Ra, —OP(O)(OH)2 or Ra;
• provided the compound is not: