Cesium carbonate → tert-Butyl 4-(4-ethylpiperazin-1-yl)-2-nitrophenylcarbamate

Participants

Role	Name	HCID	Charge
Reactant	Cesium carbonate	HCID 10796	—
Reactant	1-Ethylpiperazine	HCID 79196	—
Reactant	1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine)	HCID 636044	—
Reactant	tert-Butyl (4-bromo-2-nitrophenyl)carbamate	HCID 52904808	—
Catalyst	Bis(dibenzylideneacetone)palladium	HCID 9811564	—
Solvent	Toluene	HCID 1140	—
Solvent	Dichloromethane	HCID 6344	—
Product	tert-Butyl 4-(4-ethylpiperazin-1-yl)-2-nitrophenylcarbamate	HCID 118024395	55.4%

Reaction Conditions

Temperature	100 °C

Reaction Steps

A degassed mixture of tert-butyl 4-bromo-2-nitrophenylcarbamate (5.4 g, 17 mmol), 1-ethylpiperazine (2.91 g, 25.5 mmol), Pd2(dba)3 (2.1 g, 3.4 mmol), xantphos (3.92 g, 6.8 mmol) and Cs2CO3 (11.1 g, 34 mmol) in toluene (85 mL) was heated at 100° C. for 4 hours. The reaction was concentrated, and the residue was purified by flash chromatography on silica eluting with MeOH:DCM=1:50-1:20 to obtain the title compound (3.3 g, yield: 55%). MS (ESI): 351 [M+H]+.

Provenance & Evidence

DOI	10.6084/m9.figshare.5104873.v1
Patent number	US09434697B2
Source dataset	uspto-grants-2016_09
ORD ID	ord-66dff49ced9c44c0abf8193d3d27f5e9
Source note	uspto-grants-2016_09