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ChemicalBook CAS DataBase List 4-(5-AMINOPYRIDIN-2-YL)PIPERAZINE-1-CARBOXYLIC ACID TERT-BUTYL ESTER
119285-07-3

4-(5-AMINOPYRIDIN-2-YL)PIPERAZINE-1-CARBOXYLIC ACID TERT-BUTYL ESTER synthesis

6synthesis methods
-

Yield: 100%

Reaction Conditions:

with hydrogen;nickel in tetrahydrofuran under 2585.81 Torr; for 5 h;

Steps:

5; 8 4-(5-Amino-pyridin-2-yl)-piperazine-1-carboxylic acid tert-butyl ester
2-Bromo-5-nitro-pyridine (11.39 g, 56.1 mmol), tetrabutylammonium iodide (TBAI) (1.04 g, 0.05 mmol), potassium carbonate (8.53 g, 61.7 mmol) and piperazine-1-carboxylic acid tert-butyl ester (11.5 g, 61.7 mmol) were mixed together in DMSO (100 mL) and gently warmed to 50 C. for 3 hours and cooled to room temperature overnight. The reaction was diluted with EtOAc (200 mL), the salts were filtered and then the EtOAc was evaporated to leave the DMSO solution. This was diluted with water and a precipitate formed. This precipitate was filtered, washed with water, and then dried in an oven vacuum to give 4-(5-nitro-pyridin-2-yl)-piperazine-1-carboxylic acid tert-butyl ester (16.1 g, 93%) as a light orange solid. 1H NMR (400 MHz, CDCl3) ppm 1.47 (s, 9H), 3.55 (m, 4H), 3.75 (m, 4H), 6.55 (d, J=9.3 Hz, 1H), 8.21 (dd, J=9.5, 2.7 Hz, 1H), 9.03 (d, J=2.7 Hz, 1H). 4-(5-Nitro-pyridin-2-yl)-piperazine-1-carboxylic acid tert-butyl ester (16.0 g, 51.9 mmol) was dissolved in THF (400 mL), RaNi (4 g) added and placed under a H2 atmosphere at 50 psi for 5 h. The catalyst was removed by filtration through celite and the solvent evaporated in vacuo to give 4-(5-amino-pyridin-2-yl)-piperazine-1-carboxylic acid tert-butyl ester (14.5 g, 100%). 1H NMR (400 MHz, CDCl3) ppm 1.46 (s, 9H), 3.31 (m, 6H), 3.53 (m, 4H), 6.56 (d, J=8.8 Hz, 1H), 6.98 (dd, J=8.8, 2.9 Hz, 1H), 7.78 (dd, J=2.9, 0.7 Hz, 1H). m/z 279.1 (M+1).

References:

WARNER-LAMBERT COMPANY, LLC US2005/182078, 2005, A1 Location in patent:Page/Page column 9; 12

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