Compounds and methods for the treatment of cystic fibrosis

A compound of Formula (I)

• or a pharmaceutically acceptable salt thereof, wherein:
• R and R1 are independently selected from hydrogen, optionally substituted alkyl;
• optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted aryl, optionally substituted arylalky, optionally substituted heteroaryl or optionally substituted heteroarylalkyl;
• or R and R1, together with the nitrogen atom to which they are attached, form an optionally substituted 3 to 7-membered heterocyclyl;
• R2 is hydrogen, optionally substituted alkyl, optionally substituted aryl, optionally substituted arylalkyl, optionally substituted heteroaryl or optionally substituted heteroarylalkyl;
• R3 is hydrogen, optionally substituted alkyl, R7C(O)—, R7SO2— or R7NHC(O)—;
• or R2 and R3, together with the atoms to which they are attached, form an optionally substituted 3 to 7-membered heterocyclyl;
• Each R4 is independently halogen, optionally substituted alkyl, CN, optionally substituted alkoxy, NR12R13, or hydroxy;
• R5 is hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, or optionally substituted cycloalkyl;
• R6 is OR8, SR8 or NR9R10;
• R7 is optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted aryl, or optionally substituted arylalkyl;
• R8 is hydrogen, optionally substituted alkyl;
• optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted aryl or optionally substituted heteroaryl;
• R9 is hydrogen, OR11, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl;
• optionally substituted aryl, optionally substituted heteroaryl, heterocyclyl, SO2—R8, SO2NRaRb or N(Ra)Rb;
• R10 is hydrogen;
• optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl;
• optionally substituted aryl or optionally substituted heteroaryl;
• or R9 and R10, together with the nitrogen atom to which they are attached, form an optionally substituted heterocyclyl;
• Ra and Rb are each independently hydrogen, optionally substituted alkyl;
• optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted aryl or optionally substituted heteroaryl;
• R11 is hydrogen or optionally substituted alkyl;
• R12 and R13 are each independently hydrogen, optionally substituted alkyl, R7C(O)—, R7SO2— or R7NHC(O)—;
• or R12 and R13, together with the nitrogen atom to which they are attached, form an optionally substituted heterocyclyl;
• and
• n is 0, 1, 2, 3 or 4.