Table 2. Scope on the Ullmann coupling with methylamine (2a)^a).

Entry	1 (R, X)	Yield (%)b)	TON
1	1b (R = 3-MeO; X = I)	3ba 86% (16 h)	63.7
2	1c (R = 2-MeO; X = I)	3ca 71% (4 h)	52.6
3	1d (R = 4-Me; X = I)	3da 70% (3 h)	51.8
4	1e (R = 4-Cl; X = I)	3ea 73% (4 h)	54.0
5	1f (R = 3-MeO; X = Br)	3fa 51% (67%)c) (12 h)	49.6
6	1g (R = 3-Cl; X = Br)	3ga 51% (64%)c) (16 h)	49.4

^a)Reaction conditions: aryl iodides 1 (1 mmol), methylamine (2a, 40 wt % aqueous solution, 2.5 mL, 28.9 mmol), Cs₂CO₃ (2 mmol, 651 mg), Cu-B (20 mg, 1.35 mol% for Cu), and temperature 110°C;

^b)Isolated yields;

^c)Yields based on the recovery of starting materials.