dimethyl 3-(cyanomethylidene)pentanedioate

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

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

Procedure: To a solution of crude 3-cyanomethylene-pentanedioic acid dimethyl ester (403 g) in methanol (500 mL), 5% Pd—C was added and the mixture was stirred at room temperature for 4 days. The Pd—C was removed by filtration and the filtrate was concentrated under reduced pressure to give crude 3-cyanomethyl-pentanedioic acid dimethyl ester (212 g). The residue was purified by distillation to obtain 3-cyanomethyl-pentanedioic acid dimethyl ester (bp 130-150° C., 133 Pa) as a yellow oil. 1H NMR (200 MHz, CDCl3) δ ppm 2.46-2.61 (m, 5 H) 2.62-2.78 (m, 4 H) 3.71 (s, 6 H). The Pd—C was removed by filtration the filtrate was concentrated under reduced pressure

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

Procedure: To a solution of 3-oxo-pentanedioic acid dimethyl ester (523 g) in toluene (750 mL), cyanoacetic acid (511 g), NH4OAc (46.3 g) and acetic acid (90.1 g) were added and heated at reflux with dehydrating by Dean-Stark apparatus for 8 h. After cooling to room temperature, the reaction mixture was washed with water, saturated aqueous NaHCO3 solution and brine. The organic phase was dried over MgSO4, filtered, and concentrated under reduced pressure to give crude 3-cyanomethylene-pentanedioic acid dimethyl ester (403 g) as an oil. 1H NMR (200 MHz, CDCl3) δ ppm 3.39 (d, J=0.88 Hz, 2 H), 3.62 (s, 2 H), 3.72 (s, 3 H), 3.74 (s, 3 H), 5.51 (s, 1 H). heated at reflux with dehydrating by Dean-Stark apparatus for 8 h the reaction mixture was washed with water, saturated aqueous NaHCO3 solution and brine The organic phase was dried over MgSO4 filtered concentrated under reduced pressure

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

Procedure: To a solution of 3-oxo-pentanedioic acid dimethyl ester (523 g) in toluene (750 mL), cyanoacetic acid (511 g), NH4OAc (46.3 g) and acetic acid (90.1 g) were added and heated at reflux with dehydrating by Dean-Stark apparatus for 8 h. After cooling to room temperature, the reaction mixture was washed with water, saturated aqueous NaHCO3 solution and brine. The organic phase was dried over MgSO4, filtered, and concentrated under reduced pressure to give crude 3-cyanomethylene-pentanedioic acid dimethyl ester (403 g) as an oil. 1H NMR (200 MHz, CDCl3) δ ppm 3.39 (d, J=0.88 Hz, 2 H), 3.62 (s, 2 H), 3.72 (s, 3 H), 3.74 (s, 3 H), 5.51 (s, 1 H). heated at reflux with dehydrating by Dean-Stark apparatus for 8 h the reaction mixture was washed with water, saturated aqueous NaHCO3 solution and brine The organic phase was dried over MgSO4 filtered concentrated under reduced pressure

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

Procedure: To a solution of crude 3-cyanomethylene-pentanedioic acid dimethyl ester (403 g) in methanol (500 mL), 5% Pd—C was added and the mixture was stirred at room temperature for 4 days. The Pd—C was removed by filtration and the filtrate was concentrated under reduced pressure to give crude 3-cyanomethyl-pentanedioic acid dimethyl ester (212 g). The residue was purified by distillation to obtain 3-cyanomethyl-pentanedioic acid dimethyl ester (bp 130-150° C., 133 Pa) as a yellow oil. 1H NMR (200 MHz, CDCl3) δ ppm 2.46-2.61 (m, 5 H) 2.62-2.78 (m, 4 H) 3.71 (s, 6 H). The Pd—C was removed by filtration the filtrate was concentrated under reduced pressure

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

Procedure: To a solution of 3-oxo-pentanedioic acid dimethyl ester (523 g) in toluene (750 mL), cyanoacetic acid (511 g), NH4OAc (46.3 g) and acetic acid (90.1 g) were added and heated at reflux with dehydrating by Dean-Stark apparatus for 8 h. After cooling to room temperature, the reaction mixture was washed with water, saturated aqueous NaHCO3 solution and brine. The organic phase was dried over MgSO4, filtered, and concentrated under reduced pressure to give crude 3-cyanomethylene-pentanedioic acid dimethyl ester (403 g) as an oil. 1H NMR (200 MHz, CDCl3) δ ppm 3.39 (d, J=0.88 Hz, 2 H), 3.62 (s, 2 H), 3.72 (s, 3 H), 3.74 (s, 3 H), 5.51 (s, 1 H). heated at reflux with dehydrating by Dean-Stark apparatus for 8 h the reaction mixture was washed with water, saturated aqueous NaHCO3 solution and brine The organic phase was dried over MgSO4 filtered concentrated under reduced pressure