Diisopropylamine → 2-(Pent-1-ynyl)pyridine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a degassed solution of 2-iodopyridine (0.519 mL, 4.88 mmol), bis(triphenylphosphine)palladium(II) chloride (0.205 g, 0.293 mmol), copper(I) iodide (0.046 g, 0.244 mmol), and diisopropylamine (2.78 mL, 19.5 mmol) in N,N-dimethylformamide (20 mL) was added 1-pentyne (0.721 mL, 7.32 mmol). The reaction was heated to 85° C. for 3 hrs. The reaction mixture was cooled to room temperature, diluted with ethyl acetate (150 mL), washed with a 10% aqueous solution of lithium chloride (2×100 mL), washed with a 2M aqueous solution of ammonium hydroxide (100 mL), washed with brine (100 mL), and dried over anhydrous sodium sulfate. Concentration followed by purification by silica gel chromatography with hexanes/ethyl acetate (3/2) afforded 2-(pent-1-ynyl)pyridine (636 mg, 4.31 mmol). The compound had an HPLC retention time=0.982 min.—Column: YMC S5 COMBISCREEN® 4.6×50 mm; Gradient time: 4 min; Flow rate=4 ml/min; Solvent A=10% MeOH—90% Water—0.2% H3PO4; Solvent B=90% MeOH—10% water—0.2% H3PO4; Start % B=0; Final % B=100. LC-MS: M+1=146.3. 1H NMR (400 MHz, CDCl3) δ ppm 1.06 (t, 3H), 1.67 (dt, J=7.23 Hz, 2H), 2.43 (t, J=7.15 Hz, 2H), 7.18 (ddd, J=7.65, 4.89, 1.00 Hz, 1H), 7.38 (d, J=7.78 Hz, 1H), 7.62 (td, J=7.72, 1.88 Hz, 1H), and 8.55 (d, J=4.27 Hz, 1H).

Herkunft & Nachweise