170011-57-1

1-Boc-4-(4-aminophenyl)piperidine is a useful synthetic intermediate used in the synthesis of FMS inhibitors that may be useful in treating rheumatoid arthritis and other chronic inflammatory diseases.

General procedure for the synthesis of tert-butyl 4-(4-aminophenyl)piperidine-1-carboxylate from tert-butyl 4-(4-aminophenyl)-5,6-dihydropyridine-1(2H)-carboxylate: 4-(4-aminophenyl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester (0.35 g, 1.2 mmol) (prepared in previous step) was dissolved in methanol and added to a 10% Pd/C catalyst and hydrogenated at 20 psi hydrogen pressure for 1 hour. Upon completion of the reaction, the reaction solution was filtered to remove the catalyst and the filtrate was concentrated to give 0.35 g (100% yield) of tert-butyl 4-(4-aminophenyl)piperidine-1-carboxylate as a yellow solid. Mass spectrum (ESI, m/z): the calculated value of [M+H]+ for C16H24N2O2 was 277.2 and the measured value was 277.1.

[1] Patent: WO2006/47277, 2006, A2. Location in patent: Page/Page column 58-59
[2] Patent: US2006/281788, 2006, A1. Location in patent: Page/Page column 55
[3] Patent: US2008/51402, 2008, A1. Location in patent: Page/Page column 41
[4] Patent: US2008/114007, 2008, A1. Location in patent: Page/Page column 90
[5] Patent: US2007/60577, 2007, A1. Location in patent: Page/Page column 53