154590-35-9 tert-Butyl 4-(4-amino-2-fluorophenyl)piperazine-1-carboxylate 16203630, apiperazines compound, is more and more widely used in various fields.
With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.154590-35-9,tert-Butyl 4-(4-amino-2-fluorophenyl)piperazine-1-carboxylate,as a common compound, the synthetic route is as follows.
Step C. 2-Ethyl-N-(3-fluoro-4-piperazin-1-yl-phenyl)-butyramide. To a solution of 4-(4-amino-2-fluoro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (2.0 g, 8.9 mmol) and Et3N (1.4 mL, 10.0 mmol) in DCM (60 mL) was added 1-ethylbutyryl chloride (1.4 mL, 10.0 mol). The mixture was stirred for 18 h, quenched with 1 N NaHCO3 (50 mL), and extracted with DCM (3*50 mL). The organic layers were combined, dried (Na2SO4), and concentrated. Chromatography of the residue (SiO2; EtOAc/hexanes) gave 4-[4-(2-ethyl-butyrylamino)-2-fluoro-phenyl]-piperazine-1-carboxylic acid tert-butyl ester. Step A. 4-[4-(2-Ethyl-butyrylamino)-2-fluoro-phenyl]-piperazine-1-carboxylic acid tert-butyl ester. To a solution of 4-(4-amino-2-fluoro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (2.96 g, 10.0 mmol) and TEA (1.52 g, 15.0 mmol) in DCM (60 mL) was added 2-ethyl butyryl chloride (2.08 g, 15.0 mmol). After 18 h, the mixture was diluted with DCM (50 mL) and washed with satd. aq. NaHCO3 (1¡Á30 mL) and water (2¡Á30 mL). The organic layer was dried (Na2SO4) and concentrated. The residue was purified (SiO2; acetone/DCM and EtOAc/DCM) to yield the title compound (2.00 g, 51%). 1H NMR (CDCl3): 7.55-7.45 (m, 1H), 7.15 (br s, 1H), 7.14-7.08 (m, 1H), 6.86 (t, J=9.0, 1H), 3.62-3.54 (m, 4H), 3.01-2.93 (m, 4H), 2.04-1.96 (m, 1H), 1.76-1.65 (m, 2H), 1.60-1.50 (m, 2H), 1.48 (s, 9H), 0.94 (t, J=7.4, 6H).; Step A. 4-[4-(2-Ethyl-butyrylamino)-2-fluoro-phenyl]-piperazine-1-carboxylic acid tert-butyl ester.; To a solution of 4-(4-amino-2-fluorophenyl)piperazine-1-carboxylic acid-tert-butyl ester (3.11 g, 10.5 mmol) and TEA (1.60 g, 15.8 mmol) in DCM (50 mL) was added 2-ethylbutyryl chloride (2.17 mL, 15.8 mmol) slowly. After 18 h, the mixture was washed with water, dried (Na2SO4), and concentrated. The residue was purified twice [SiO2; 1) acetone/DCM, 2) EtOAc/hexanes] to give the title compound. (2.07 g, 50%)., 154590-35-9
154590-35-9 tert-Butyl 4-(4-amino-2-fluorophenyl)piperazine-1-carboxylate 16203630, apiperazines compound, is more and more widely used in various fields.
Reference£º
Patent; Bonaventure, Pascal; Carruthers, Nicholas I.; Chai, Wenying; Dvorak, Curt A.; Jablonowski, Jill A.; Rudolph, Dale A.; Seierstad, Mark; Shah, Chandravadan R.; Swanson, Devin M.; Wong, Victoria D.; US2007/100141; (2007); A1;,
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