反应详情

A flask was flushed with nitrogen and charged with 20% palladium hydroxide on carbon (91 mg, 0.647 mmol). A solution of (3R,4R)-tert-butyl 3-ethyl-4-(((R)-1-phenylethyl)amino)piperidine-1-carboxylate (430.5 mg, 1.295 mmol) in acetic acid (8.6 ml) was added. The flask was flushed with nitrogen, sealed, evacuated briefly, and charged with hydrogen. The mixture was stirred at room temperature for 14 hrs. The flask was evacuated, backfilled with nitrogen, and opened. The reaction mixture is filtered through celite. The filtrate was concentrated by azeotropical distillation with toluene (3×25 ml) under reduced pressure to remove the residual acetic acid, yielding (3R,4R)-tert-butyl 4-amino-3-ethylpiperidine-1-carboxylate, HOAc salt (351 mg, 1.217 mmol, 94.0% yield) as a white solid. 1H NMR (400 MHz, methanol-d4) δ 4.16 (d, J=11.2 Hz, 1H), 4.07 (d, J=13.9 Hz, 1H), 3.03-2.85 (m, 2H), 2.56 (br. s., 1H), 2.02-1.94 (m, 1H), 1.92 (s, 3H), 1.77-1.66 (m, 1H), 1.53-1.36 (m, 10H), 1.32-1.16 (m, 1H), 1.00 (t, J=7.5 Hz, 3H).

1. customA flask was flushed with nitrogen
2. customThe flask was flushed with nitrogen
3. customsealed
4. customevacuated briefly
5. additioncharged with hydrogen
6. customThe flask was evacuated
7. filtrationThe reaction mixture is filtered through celite
8. concentrationThe filtrate was concentrated by azeotropical distillation with toluene (3×25 ml) under reduced pressure
9. customto remove the residual acetic acid