Sodium Hydroxide → tert-butyl (3R,4S)-3-fluoro-4-hydroxypiperidine-1-carboxylate

Temperature

0 °C

To a solution of 0.5 g (2.30 mmol) of N-Boc-3-fluoro-4-piperidinone 2 (J. Med. Chem. 1999, 42, 2087-2104) in 10 mL of dry THF was added dropwise 2.8 mL (2.76 mmol) of a 1M solution of Li-selectride in THF under N2-atmosphere at 0° C. The solution was stirred at 0° C. for 4 h, then 10 mL of NaOH 2M was added at 0° C. and the mixture was stirred overnight at rt. The reaction mixture was extracted with Et2O, dried over MgSO4, filtered and evaporated under reduced pressure. The crude mixture was subjected to flash silicagel chromatography (hex/EtOAc/Et3N 1:1:0.1) to yield 0.27 g (56%) of pure cis-1-Boc-3-fluoro-4-hydroxypiperidine 3 as a colorless oil which solidified upon standing at −20° C. (freezer). Mp 48° C. 1H NMR (300 MHz, CDCl3): δ 1.46 (9H, s, 3×CH3), 1.67-1.91 (2H, m, CH2), 2.40-2.65 (1H, m, OH), 2.92-3.35 (2H, m, CH2CHaCHbN and CHaHbCHF), 3.55-3.94 (3H, m, CH2CHaHbN and CHOH and CHaHbCHF), 4.52 (1H, dm, J=48.4 Hz, CHF). 19F NMR (282 MHz, CDCl3): δ −201.9 and −203.1 (1F, 2×m). 13C NMR (75 MHz, CDCl3): δ 28.4 (3×), 29.2, 40.4, 44.8, 68.0 (d, J=17.3 Hz), 80.2, 88.6 (d, J=177.7 Hz), 155.1. IR (KBr): v 3413, 1674, 1429, 1167 cm−1. GC-MS (EI): m/z (%): 219 (M+, 4), 164 (46), 146 (50), 57 (C4H9+, 100).

1. stirringthe mixture was stirred overnight at rt
2. extractionThe reaction mixture was extracted with Et2O
3. dry with materialdried over MgSO4
4. filtrationfiltered
5. customevaporated under reduced pressure

ORD record

ord-525eb7ef9076487094dc47a41e17da71

Source dataset

uspto-grants-2014_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08703958B2