Carbamoylation of primary, secondary and aromatic amines by dimethyl carbonate in a flow system over solid catalysts

Sustainable Chemical Processes

Table 3 Carbamoylation of n-hexylamine with DMC in the presence of different catalysts

Catalyst	Temperature [°C]	*Yield of carbamate [%]**	Conversion of amine [%]	Selectivity towards carbamate [%]
-	50	8.4	10.4	80.8
	80	28.6	34.1	83.9
	120	31.1	37.4	83.2
	150	52.4	67.2	78.0
98% Fe₂O₃	50	7.9	9.8	81.0
	80	31.3	38.3	81.7
	120	42.8	49.5	86.5
	150	63.5	77.0	82.5
Fe₂O₃/SiO₂	50	5.2	10.8	48.0
	80	26.1	34.6	75.5
	120	32.8	45.5	72.1
	150	51.3	72.1	71.2
T-4419	50	5.5	7.1	77.7
	80	17.0	22.8	74.5
	120	28.3	39.3	72.1
	150	41.0	65.1	63.0
Fe₂O₃/CoO/NiO/SiO₂	50	5.5	6.9	79.6
	80	27.7	34.2	81.1
	120	35.9	43.9	81.7
	150	59.4	73.2	81.2
TZC-3/1	50	9.2	11.3	81.1
	80	34.8	42.5	81.9
	120	51.8	61.4	84.3
	150	68.3	83.1	82.2

*GC-yield versus amine.
Molar ratio of amine: DMC = 2:1, WHSV = 4 g amine/1 g catalyst · h, reactant mixture pressure = 9.0 MPa.
The number of replicates was 3.