4-奎宁环甲醛

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of quinuclidine-4-carbaldehyde (0.57 g, 4.10 mmol), piperidine (0.86 g, 1 mL, 10.10 mmol), methyl 2-amino-3-hydroxybenzoate (0.68 g, 4.10 mmol) and methanol (10 mL) was heated to reflux for 40 h. Analysis by LCMS indicated the presence of the requisite intermediate Schiff base. The solvent was removed under reduced pressure, the residue was dissolved in methylene chloride (20 ml) and silver (I) oxide (1.23 g, 5.34 mmol) was added. The reaction mixture was stirred at room temperature for 5 h. Analysis by LCMS indicated consumption of the Schiff base intermediate. The reaction mixture was filtered though diatomaceous earth (10 g) eluting with methylene chloride (50 mL) and concentrated. The crude product was purified by column chromatography (silica gel, 5 to 20% methanol in chloroform) to afford methyl 2-(quinuclidin-4-yl)benzoxazole-4-carboxylate (250 mg, 17%) as an brown solid: 1H NMR (300 MHz, CDCl3) δ 7.96 (dd, J=8.0, 1.0 Hz, 1H), 7.67 (dd, J=8.0, 1.0 Hz, 1H), 7.37 (d, d, J=8.0 Hz, 1H), 4.01 (s, 3H), 3.06-3.02 (m, 6H), 2.06-2.01 (m, 6H); MS (ESI+) m/z 287 (M+H). was heated to reflux for 40 h The solvent was removed under reduced pressure the residue was dissolved in methylene chloride (20 ml) consumption of the Schiff base intermediate The reaction mixture was filtered though diatomaceous earth (10 g) eluting with methylene chloride (50 mL) concentrated The crude product was purified by column chromatography (silica gel, 5 to 20% methanol in chloroform)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of quinuclidine-4-carbaldehyde (0.57 g, 4.10 mmol), piperidine (0.86 g, 1 mL, 10.10 mmol), methyl 2-amino-3-hydroxybenzoate (0.68 g, 4.10 mmol) and methanol (10 mL) was heated to reflux for 40 h. Analysis by LCMS indicated the presence of the requisite intermediate Schiff base. The solvent was removed under reduced pressure, the residue was dissolved in methylene chloride (20 ml) and silver (I) oxide (1.23 g, 5.34 mmol) was added. The reaction mixture was stirred at room temperature for 5 h. Analysis by LCMS indicated consumption of the Schiff base intermediate. The reaction mixture was filtered though diatomaceous earth (10 g) eluting with methylene chloride (50 mL) and concentrated. The crude product was purified by column chromatography (silica gel, 5 to 20% methanol in chloroform) to afford methyl 2-(quinuclidin-4-yl)benzoxazole-4-carboxylate (250 mg, 17%) as an brown solid: 1H NMR (300 MHz, CDCl3) δ 7.96 (dd, J=8.0, 1.0 Hz, 1H), 7.67 (dd, J=8.0, 1.0 Hz, 1H), 7.37 (d, d, J=8.0 Hz, 1H), 4.01 (s, 3H), 3.06-3.02 (m, 6H), 2.06-2.01 (m, 6H); MS (ESI+) m/z 287 (M+H). was heated to reflux for 40 h The solvent was removed under reduced pressure the residue was dissolved in methylene chloride (20 ml) consumption of the Schiff base intermediate The reaction mixture was filtered though diatomaceous earth (10 g) eluting with methylene chloride (50 mL) concentrated The crude product was purified by column chromatography (silica gel, 5 to 20% methanol in chloroform)