Compounds and Compositions That Bind and Stabilize Transthyretin and Their Use for Inhibiting Transthyretin Amyloidosis and Protein-Protein Interactions

A compound of Formula (Ib) or (Ic)

• wherein
• Xa, Xb, and Xc, are each independently selected from C(R4)(R5), O, N—R5 or S;
• wherein R4 and R5 are independently selected from hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, alkoxy, aryloxy, hydroxyl, a heterocyclic group, halogen, nitro, acyl, substituted acyl, carboxyl, alkoxycarbonyl, substituted alkoxycarbonyl, aminoacyl, substituted aminoacyl, amino, substituted amino, acylamino, substituted acylamino, and cyano;
• R1 and R2, when present, are each independently selected from hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, aryl, substituted aryl, alkoxy, aryloxy, hydroxyl, a heterocyclic group, halogen, nitro, acyl, substituted acyl, carboxyl, alkoxycarbonyl, substituted alkoxycarbonyl, aminoacyl, substituted aminoacyl, amino, substituted amino, acylamino, substituted acylamino, and cyano;
• ring A is a 4- to 12-membered ring, in certain embodiments the 4- to 12-membered ring is an aromatic or heteroaromatic ring;
• each Y is independently selected from hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, alkoxy, aryloxy, hydroxyl, a heterocyclic group, halogen, nitro, acyl, substituted acyl, carboxyl, alkoxycarbonyl, substituted alkoxycarbonyl, aminoacyl, substituted aminoacyl, amino, substituted amino, acylamino, substituted acylamino, sulfonamide, sulfonyl fluoride, thioester, and cyano;
• and
• c is a number from zero to 5;
• or a pharmaceutically acceptable salt, ester, enol ether, enol ester, amide, acetal, ketal, orthoester, hemiacetal, hemiketal, hydrate, solvate or prodrug thereof.