Cesium carbonate → Tert-butyl 4-(3-methyl-4-nitrophenoxy)piperidine-1-carboxylate

Temperature

90 °C

Cesium carbonate (11.76 g, 26.11 mmoles, 2 equivalents) was added to a stirred solution of 3-methyl-4-nitrophenol (2.76 g, 18.05 mmoles, 1 equivalent) and tert-butyl 4-(methylsulfonyloxy)piperidine-1-carboxylate (7.34 g, 19.96 mmoles, 1.1 equivalents) in anhydrous DMA (50 mls). The stirred reaction mixture was then heated to 90° C. (thermostatically controlled heating mantle) for 22 hours. The reaction mixture was then allowed to cool to room temperature and was filtered through a plug of Celite. The reaction flask and the Celite were then washed with ethyl acetate (250 ml). The organic solution was then transferred to a separatory funnel and extracted with additional ethyl acetate (3×200 ml). The combined ethyl acetate solution was then washed with water (2×100 ml), saturated sodium chloride (2×100 ml), dried over anhydrous magnesium sulfate, filtered and evaporated under reduced pressure to give a product. This material was triturated with diethylether to give a crystalline solid which was filtered off, washed with diethylether and dried under reduced pressure to give 5.2 g of tert-butyl 4-(3-methyl-4-nitrophenoxy)piperidine-1-carboxylate (yield=82%). 1H-NMR (400 MHz, DMSO-d6) δ 8.80 (s, 1H), 7.89 (d, 1H), 7.74 (d, 1H), 3.82 (d, 2H), 3.65 (m, 2H), 2.40 (s, 3H), 1.76 (m, 1H), 1.54 (m, 2H), 1.38 (s, 9H), 0.98 (m, 2H). MS (EI): 351 (MH+).

1. customThe stirred reaction mixture
2. temperaturethermostatically controlled heating mantle) for 22 hours
3. temperatureto cool to room temperature
4. filtrationwas filtered through a plug of Celite
5. washThe reaction flask and the Celite were then washed with ethyl acetate (250 ml)
6. customThe organic solution was then transferred to a separatory funnel
7. extractionextracted with additional ethyl acetate (3×200 ml)
8. washThe combined ethyl acetate solution was then washed with water (2×100 ml), saturated sodium chloride (2×100 ml)
9. dry with materialdried over anhydrous magnesium sulfate
10. filtrationfiltered
11. customevaporated under reduced pressure
12. customto give a product
13. customThis material was triturated with diethylether
14. customto give a crystalline solid which
15. filtrationwas filtered off
16. washwashed with diethylether
17. customdried under reduced pressure

ORD record

ord-91317410c0074d83b5501b2a66dd4429

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08088767B2