Heterocyclic inhibitors of histamine receptors for the treatment of disease

A compound of structural Formula (I):

• or a salt thereof, wherein:
• the ring comprising X1-X5 is aromatic;
• X1 and X5 are independently chosen from C, CH and N;
• X2 is chosen from [C(R6)(R7)], NR8, O and S;
• X3 is chosen from [C(R9)(R10)], NR11, O, and S;
• X4 is chosen from [C(R12)(R13)], NR14, O and S;
• X6 is chosen from CR18 and N;
• X7 is chosen from CR19 and N;
• Y1 is chosen from a bond, lower alkyl, lower alkoxy, OR15, NR16R17, and lower aminoalkyl;
• Y2 is chosen from a bond, lower alkyl, lower alkoxy, OR20, NR21R22, S, S(O), S(O)2, S(O)2NH2, S(O)2NHR23, S(O)2NR23R24, C(O)NH2, C(O)NHR23, C(O)NR23R24 and lower aminoalkyl;
• R1 is selected from the group consisting of:
• aryl, heterocycloalkyl, cycloalkyl, and heteroaryl, any of which may be optionally substituted, when Y1 is a bond;
• and
• null, when Y1 is chosen from OR15, NR16R17, lower alkyl, lower alkoxy, or lower aminoalkyl;
• R2 is chosen from alkyl, aryl, cycloalkyl, heterocycloalkyl and heteroaryl, any of which may be optionally substituted;
• R6, R7, R9, R10, R12, R13, R18, and R19 are independently chosen from null, hydrogen, alkyl, alkynyl, heteroalkyl, alkoxy, halogen, haloalkyl, perhaloalkyl, amino, aminoalkyl, amido, carboxyl, acyl, hydroxy, cyano, nitro, aryl, arylalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, heteroaryl, and heteroarylalkyl, any of which may be optionally substituted;
• R8, R11, and R14 are independently chosen from null, hydrogen, alkyl, heteroalkyl, alkoxy, haloalkyl, perhaloalkyl, aminoalkyl, C-amido, carboxyl, acyl, hydroxy, aryl, arylalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, heteroaryl, and heteroarylalkyl, any of which may be optionally substituted;
• R15, R16, R20, and R21 are independently chosen from aminoalkyl, alkylaminoalkyl, aryl, arylalkyl, cycloalkyl, cycloalkylalkyl, ether, heterocycloalkyl, lower alkylaminoheterocycloalkyl, heterocycloalkylalkyl, heteroaryl, and heteroarylalkyl, any of which may be optionally substituted;
• R17 and R22 are independently chosen from hydrogen, aminoalkyl, alkylaminoalkyl aryl, arylalkyl, cycloalkyl, cycloalkylalkyl, ether, heterocycloalkyl, lower alkylaminoheterocycloalkyl, heterocycloalkylalkyl, heteroaryl, and heteroarylalkyl, any of which may be optionally substituted;
• and
• R23 and R24 are independently chosen from hydrogen, alkyl, alkenyl, alkynyl, heteroalkyl, alkoxy, halogen, haloalkyl, perhaloalkyl, perhaloalkoxy, amino, aminoalkyl, amido, carboxyl, acyl, hydroxy, cyano, nitro, aryl, arylalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, heteroaryl, and heteroarylalkyl, any of which may be optionally substituted.