tert-butyl 3-endo-hydroxy-8-azabicyclo[3.2.1]octane-8-carboxylate

Synthesis

General procedure for the synthesis of tert-butyl 3-endo-3-hydroxy-8-azabicyclo[3.2.1]octane-8-carboxylate from di-tert-butyl dicarbonate and endo-8-azabicyclo[3.2.1]octan-3-ol: endo-8-azabicyclo[3.2.1]octan-3-ol (3.6 g, 28.3 mmol) was dissolved in dichloromethane (50 mL) and the solution was cooled to 0°C. Triethylamine (7.8 mL, 56.7 mmol) and di-tert-butyl dicarbonate (7.4 g, 33.9 mmol) were added sequentially with stirring. The reaction mixture was gradually warmed to room temperature and stirring was continued for 12 hours. After completion of the reaction, the reaction mixture was diluted with distilled water. The organic layer was separated and washed sequentially with saturated aqueous citric acid solution, distilled water and saturated saline. The organic layer was dried with anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to afford tert-butyl 3-endo-3-hydroxy-8-azabicyclo[3.2.1]octane-8-carboxylate as a white solid (6.45 g, 28.4 mmol, 100% yield). Mass spectrum (ESI) m/z: 228 [M + H]+.

References

[1] Patent: WO2007/63071, 2007, A1. Location in patent: Page/Page column 15
[2] Patent: US2007/123525, 2007, A1. Location in patent: Page/Page column 20
[3] Patent: WO2016/91776, 2016, A1. Location in patent: Page/Page column 210; 211
[4] Patent: WO2014/152144, 2014, A1. Location in patent: Paragraph 0190
[5] Patent: WO2009/106534, 2009, A1. Location in patent: Page/Page column 73