Diisobutylaluminum hydride → 3-(1-Methylpyrrolidin-2-yl)pyridine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of 2′-cyanonicotine 3 (324 mg, 1.73 mmol) in toluene (12.4 mL) was treated at −78° C. with DIBALH (8.65 mL of a 1.0 M solution in hexane, 8.65 mmol). After the reaction mixture had been stirred for an additional 3 h at −78° C., it was quenched by slow addition of saturated aqueous solution of NH4Cl. The resulting mixture was allowed to warm to room temperature. The organic layer was separated and the aqueous layer was extracted with methylene chloride. The combined organic extracts were dried over MgSO4 and concentrated in vacuo. The crude mixture was purified by flash chromatography on silica gel (CH2Cl2/CH3OH/NH4OH concd 95:5:0.1) to give (±)-2′-aminomethylnicotine 8 as a clear oil (195.1 mg, 1.02 mmol, 59%) as well as nicotine (11 mg, 0.07 mmol, 4%). 1H NMR (300 MHz, CDCl3): δ=8.60 (d, 1H, J=2.7 Hz, ArH), 8.48 (dd, 1H, J=1.8, 4.8 Hz, ArH), 7.64 (dt, 1H, J=8.1, 1.8 Hz, ArH), 7.28 (ddd, 1H, J=8.1, 4.8, 0.9 Hz, ArH), 3.21 (d, 1H, J=12.9 Hz), 3.03 (d, 1H, J=12.9 Hz), 3.00 (m, 1H), 2.74 (m, 1H), 2.18 (m, 2H), 2.17 (s, 3H, NCH3), 1.93 (m, 2H), 1.32 (bs, 2H, NH2). —13C NMR (75.3 MHz, CDCl3): δ=149.1 (CH), 148.0 (CH), 138.3 (C), 135.0 (CH), 123.2 (CH), 68.0 (C), 54.8 (CH2), 46.5 (CH2), 36.5 (CH2), 35.5 (CH3), 22.5 (CH2). HRMS (ESI) m/z: found for [M+H]+ 192.1490. Calcd for C11H17N3 192.1495.

Herkunft & Nachweise