4-(4-Aminophenyl)piperazine-1-carboxylic acid tert-butyl ester

Pd on C 10percent (0.3 percent p/p) was added to a solution of terf-butyl 4-(4-nitrophenyl)piperazine-l-carboxylate (1 eq) in a mixture (1 : 1 ratio) MeOH : EtOAc (0.03 M). The atmosphere in the reaction vessel was charged with Hferf-Butyl 4-(4-nitrophenyl)piperazine-1-carboxylate (11) (3.24 g, 10.5 mmol) was dissolved in EtOAc (90 mL) under an atmosphere of nitrogen and a slurry of 10percent Pd/C (0.500 g) in EtOAc (10 mL) was added. The resulting suspension was then stirred vigorously under an atmosphere of hydrogen at room temperature for 42 hours. The catalyst was removed by filtration through Celite, which was washed with EtOAc (7 x 10 mL) and the solvent was removed in vacuo to give the title compound (12) (2.92 g, 99 percent yield) as a pale pink solid; tert-Butyl 4-(4-nitrophenyl)piperazine-1-carboxyiate (11) (3.24 g, 10.5 mmol) was dissolved in EtOAc (90 mL) under an atmosphere of nitrogen and a slurry of 10percent Pd/C (0.500 g) in EtOAc (10 mL) was added. The resulting suspension was then stirred vigorously under an atmosphere of hydrogen at room temperature for 42 hours. The catalyst was removed by filtration through Celite, which was washed with EtOAc (7 x 10 mL) and the solvent was removed in vacuo to give the title compound (12) (2.92 g, 99 percent yield) as a pale pink solid; 4-(4-Nitrophenyl)-1-piperazinecarboxylic acid, 1, 1-dimethylethyl ester (20 g, 65 mmol) was dissolved in anhydrous ethanol (250 mL) and 10percent Pd/C (1.8 g) was added. A solution of tert-butyl 4-(4-nitrophenyl)piperazine- 1 -carboxylate (8.2 g, 26.68 mmol) inMeOH (100 mL) was purged using nitrogen and reduced pressure. Palladium on charcoal(10percent wet) was added and the mixture was hydrogenated (50 psi) for 16 h. The reaction mixture was filtered through diatomaceous earth and concentrated under reduced pressure to give tert-butyl 4-(4-aminophenyl)piperazine-1-carboxylate (7.4 g, 97percent) as a dark blue oil used directly into the next step. C15H23N302 MS m/z 277.9 (M+H).To the reaction flask was added compound 40 (17.57 g, 63.39 mmol)Soluble in methanol, Add 1.7 g of Pd / C, Catalytic hydrogenation at room temperature, TLC tracking, to be completely complete, Diatomaceous earth filtration, The solvent was removed by distillation under reduced pressure, To obtain a crude solid, And then beaten with ether to get pink powder, Drying to give 12.31 g of compound 7-11, Yield: 73.8percent.1 equiv of 43 dissolved in methanol (anhydrous) and 10percent of 10percent Pd/C was added under a hydrogen atmosphere and allowed to stir overnight at room-temp. The solvent was removed and the residue was taken up with methanol, Pd-C (10percent) was added and stirred under hydrogen overnight at room temperature and then filtered through Celite and concentrated in vacuo. The crude product was purified by flash chromatography to afford 0.457 g product (60percent).A mixture of 4-iodoaniline (0.654 g, 3 mmol), piperazine-1-carboxylic acid tert-bvyl ester (0.67 g, 3.6 mmol), potassium phosphate (1.272 g, 6 mmol), ethylene glycol (0.33 ml) and copper iodide (0.03 g, 0.15 mmol) in 2-propanol (3 ml) was placed under argon in a sealed-tube and heated to 8OAdding aniline, piperazine-1-carboxylic acid tert-butyl ester, acridine salt visible light catalyst, 2, 2, 6, 6-tetramethylpiperidine-nitrogen-oxide to anhydrous dichloroethane, The reaction environment was then replaced with oxygen three times and irradiated with a blue LED for a reaction time of 10 h.After the reaction is completed, the filtrate is spun dry and separated by column chromatography.The title product was obtained as a colorless white solid, yield 95percent.

Molecular Weight:277.36
XLogP3:2
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:3
Exact Mass:277.17902698
Monoisotopic Mass:277.17902698
Topological Polar Surface Area:58.8
Heavy Atom Count:20
Complexity:325
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes