Aryl aniline derivatives as beta2 adrenergic receptor agonists

A process for preparing a compound of formula (I):

• wherein:
• R1 is —CH2OH or —NHCHO, and R2 is hydrogen,
• or R1 and R2 taken together are —NHC(═O)CH═CH—, or —CH═CHC(═O)NH—;
• R3 is —OH, and R4 is hydrogen,
• one of R5 and R6 is —[O—C1-6alkylenyl]n—NR10R11 or C1-6alkylenyl-NR12R13,
• and the other of R5 and R6 is selected from hydrogen, hydroxy, C1-4alkoxy, and C1-4alkyl, wherein C1-4alkyl is optionally substituted with halo,
• wherein
• each of R10, R11, R12, and R13 is independently hydrogen or C1-4alkyl;
• or
• R10 and R11, together with the nitrogen atom to which they are attached, or R10, together with the nitrogen atom to which it is attached and a carbon atom of the adjacent C1-6alkylenyl, or R12 and R13, together with the nitrogen atom to which they are attached, or R12, together with the nitrogen atom to which it is attached and a carbon atom of the adjacent C1-6alkylenyl, form a heterocyclic or heteroaryl ring having from 5 to 7 ring atoms, and optionally containing an additional heteroatom selected from oxygen, nitrogen, and sulfur, wherein nitrogen is optionally substituted with —S(O)2—C1-4alkyl;
• and
• n is 1, 2, or 3;
• and
• each of R7, R8, and R9 is hydrogen;
• or a pharmaceutically-acceptable salt or stereoisomer thereof,
• the process comprising:
• (a) reacting
• (i) a compound of formula (III):
• with a compound of formula (IV):
• in the presence of a transition metal catalyst;
• or
• (ii) a compound of formula (V):
• with a compound of formula (VI):
• wherein P1 is a hydroxy-protecting group;
• and R3a is —OH or —OP2, wherein P2 is a hydroxy-protecting group;
• one of A and B is a leaving group and the other of A and B is —NH2;
• L is a leaving group;
• to provide a compound of formula (VII);
• (b) removing the protecting group P1 to provide a compound of formula (VIII):
• and
• (c) when R3a, is —OP2, removing the protecting group P2 to provide a compound of formula (I), or a salt or stereoisomer thereof.