Oxidative Carbonylation of Aromatic Amines with CO Catalyzed by 1,3-Dialkylimidazole-2-selenone in Ionic Liquids

Table 3

The synthesis of symmetrical ureas from organic amines.

Entry^a	Substrates	Products	BMIM]BF4 (g)	(°C)	Yield (%)^c
1 [19]			0.25	90	94
2 [19]			0.25	90	97
3 [19]			0.25	90	17
4 [19]			0.25	90	7
5 [20]			0.25	90	41
6 [21]			0.25	90	40
7 [3]			0.25	60	70
8 [3]			—	60	73
9^b [22]	CH3CH2NH2	CH3CH2NHCONHCH2CH3	—	60	52
10			—	60	0
11 [22]	(CH3)(CH2)3NH2	(CH3)(CH2)3NHCONH(CH2)3CH3	—	60	91
12 [22]	(CH3)2CHNH2	(CH3)2CHNHCONHCH(CH3)2	—	60	97
13 [19]			—	60	98

^aReaction conditions: catalyst a (0.10 g), [BMIM]BF₄ (0.25 g), amine (5.0 mmol); Pair + Pco = 1.3 Mpa; reaction time = 6 h; ^b65–75% aqueous solution; ^cisolated yields.