methyl piperidine-4-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-Methoxybenzyl chloride (1.10 g, 6.98 mmol) was added dropwise to a solution of isonipecotic acid methyl ester (1.00 g, 6.98 mmol) and triethylamine (1.40 g, 14 mmol) in THF (30 ml) and the mixture was stirred at 60° C. for 72 h. 5% strength sodium bicarbonate solution (50 ml) was then added to the reaction mixture and the mixture was extracted with ethyl acetate (3×50 ml). The combined organic phases were dried with sodium sulfate and concentrated i. vac. The residue was purified by flash chromatography with cyclohexane/ethyl acetate (2:1). the mixture was extracted with ethyl acetate (3×50 ml) The combined organic phases were dried with sodium sulfate concentrated i The residue was purified by flash chromatography with cyclohexane/ethyl acetate (2:1)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 4-[(5E)-5-(5,6-difluoro-2-oxo-1,2-dihydro-3H-indol-3-ylidene)-2,2-dimethyl-2,5-dihydrofuran-3-yl]benzaldehyde (60 mg, 0.16 mmol), methyl isonipecotate (50 mg, 0.35 mmol), and 100 mg of 4 Å molecular sieves in 5 mL of anhydrous DMF was stirred under nitrogen for 16 hours. Acetic acid (20 mg) and 1M sodium cyanoborohydride/THF solution (0.35 mL, 0.35 mmol) were then added. The mixture was diluted with 5 mL of anhydrous methanol, stirred at room temperature for 1 hour, and poured into 100 mL of water with stirring. The resulting precipitates were filtered, washed with water, and dried in vacuo to give the crude product, which was purified through silica gel column with 1-5% MeOH/CHCl3 to give methyl 1-{4-[(5E)-5-(5,6-difluoro-2-oxo-1,2-dihydro-3H-indol-3-ylidene)-2,2-dimethyl-2,5-dihydrofuran-3-yl]benzyl}piperidine-4-carboxylate as yellow solid. Yield: 50 mg, 62%. stirred at room temperature for 1 hour with stirring The resulting precipitates were filtered washed with water dried in vacuo to give the crude product, which was purified through silica gel column with 1-5% MeOH/CHCl3

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 4-[(5E)-5-(5,6-difluoro-2-oxo-1,2-dihydro-3H-indol-3-ylidene)-2,2-dimethyl-2,5-dihydrofuran-3-yl]benzaldehyde (60 mg, 0.16 mmol), methyl isonipecotate (50 mg, 0.35 mmol), and 100 mg of 4 Å molecular sieves in 5 mL of anhydrous DMF was stirred under nitrogen for 16 hours. Acetic acid (20 mg) and 1M sodium cyanoborohydride/THF solution (0.35 mL, 0.35 mmol) were then added. The mixture was diluted with 5 mL of anhydrous methanol, stirred at room temperature for 1 hour, and poured into 100 mL of water with stirring. The resulting precipitates were filtered, washed with water, and dried in vacuo to give the crude product, which was purified through silica gel column with 1-5% MeOH/CHCl3 to give methyl 1-{4-[(5E)-5-(5,6-difluoro-2-oxo-1,2-dihydro-3H-indol-3-ylidene)-2,2-dimethyl-2,5-dihydrofuran-3-yl]benzyl}piperidine-4-carboxylate as yellow solid. Yield: 50 mg, 62%. stirred at room temperature for 1 hour with stirring The resulting precipitates were filtered washed with water dried in vacuo to give the crude product, which was purified through silica gel column with 1-5% MeOH/CHCl3

Conditions: temp:0.00; pressure:0.00; stir: