ethyl 2,5-dioxopyrrolidine-3-carboxylate

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 ethyl 2,5-dioxopyrrolidine-3-carboxylate (2.96 g) in ethyl acetate (25 ml) were added di-tert-butyl azodicarboxylate (4.19 g) and then potassium carbonate (4.78 g) at room temperature. After this reaction mixture was stirred at room temperature for 15 minutes, the resulting mixture was filtered through a Celite pad and the filtrate was concentrated. The residue was purified by a flash column chromatography (hexane:ethyl acetate=3:1) to give ethyl 3-[N,N′-bis(tert-butyloxycarbonyl)hydrazino]-2,5-dioxopyrrolidine-3-carboxy late (5.77 g, 83%) as amorphous. at room temperature the resulting mixture was filtered through a Celite pad the filtrate was concentrated The residue was purified by a flash column chromatography (hexane:ethyl acetate=3:1)

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

Procedure: To a solution of ethyl 2,5-dioxopyrrolidine-3-carboxylate (3.92 g) in ethyl acetate (60 ml) was added dibenzyl azodicarboxylate (7.27 g), followed by potassium carbonate (317 mg) at room temperature. After this mixture was stirred at room temperature for 1 hour, the mixture was filtered through a Celite pad. The filtrate was concentrated and the resulting residue was purified by a flash column chromatography (hexane:ethyl acetate=2:1) to give the ethyl 3-[N,N′-bis(benzyloxycarbonyl)hydrazino]-2,5-dioxopyrrolidine-3-carboxylate (10.1 g, 94%) as amorphous. the mixture was filtered through a Celite pad The filtrate was concentrated the resulting residue was purified by a flash column chromatography (hexane:ethyl acetate=2:1)

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

Procedure: To a solution of diethyl malonate (6.1 ml) in N,N-dimethylformamide (30 ml) are added 60% sodium hydride (1.6 g) at 0° C. and, after 8 minutes, chloroacetamide (1.87 g). After stirring at room temperature for 3.5 hours, the mixture in neutralized with acetic acid and extracted with ethyl acetate. The extract is washed with water and concentrated to give 2,5-dioxopyrrolidine-3-carboxylic acid ethyl ester. Oil. the mixture in neutralized with acetic acid and extracted with ethyl acetate The extract is washed with water concentrated

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

Procedure: To a solution of diethyl malonate (6.1 ml) in N,N-dimethylformamide (30 ml) are added 60% sodium hydride (1.6 g) at 0° C. and, after 8 minutes, chloroacetamide (1.87 g). After stirring at room temperature for 3.5 hours, the mixture in neutralized with acetic acid and extracted with ethyl acetate. The extract is washed with water and concentrated to give 2,5-dioxopyrrolidine-3-carboxylic acid ethyl ester. Oil. the mixture in neutralized with acetic acid and extracted with ethyl acetate The extract is washed with water concentrated

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 ethyl 2,5-dioxopyrrolidine-3-carboxylate (2.96 g) in ethyl acetate (25 ml) were added di-tert-butyl azodicarboxylate (4.19 g) and then potassium carbonate (4.78 g) at room temperature. After this reaction mixture was stirred at room temperature for 15 minutes, the resulting mixture was filtered through a Celite pad and the filtrate was concentrated. The residue was purified by a flash column chromatography (hexane:ethyl acetate=3:1) to give ethyl 3-[N,N′-bis(tert-butyloxycarbonyl)hydrazino]-2,5-dioxopyrrolidine-3-carboxy late (5.77 g, 83%) as amorphous. at room temperature the resulting mixture was filtered through a Celite pad the filtrate was concentrated The residue was purified by a flash column chromatography (hexane:ethyl acetate=3:1)

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

Procedure: To a solution of ethyl 2,5-dioxopyrrolidine-3-carboxylate (3.92 g) in ethyl acetate (60 ml) was added dibenzyl azodicarboxylate (7.27 g), followed by potassium carbonate (317 mg) at room temperature. After this mixture was stirred at room temperature for 1 hour, the mixture was filtered through a Celite pad. The filtrate was concentrated and the resulting residue was purified by a flash column chromatography (hexane:ethyl acetate=2:1) to give the ethyl 3-[N,N′-bis(benzyloxycarbonyl)hydrazino]-2,5-dioxopyrrolidine-3-carboxylate (10.1 g, 94%) as amorphous. the mixture was filtered through a Celite pad The filtrate was concentrated the resulting residue was purified by a flash column chromatography (hexane:ethyl acetate=2:1)

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

Procedure: To a solution of ethyl 2,5-dioxopyrrolidine-3-carboxylate (2.96 g) in ethyl acetate (25 ml) was added di-tert-butyl azodicarboxylate (4.19 g), followed by potassium carbonate (4.78 g) at room temperature. After this reaction mixture was stirred at room temperature for 15 minutes, the resulting mixture was filtered through a Celite pad and the filtrate was concentrated. The residue was purified by a flash column chromatography (hexane:ethyl acetate=3:1) to give the desired product (5.77 g, 83%) as amorphous. the resulting mixture was filtered through a Celite pad the filtrate was concentrated The residue was purified by a flash column chromatography (hexane:ethyl acetate=3:1)

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

Procedure: To a solution of ethyl 2,5-dioxopyrrolidine-3-carboxylate (3.92 g) in ethyl acetate (60 ml) was added dibenzyl azodicarboxylate (7.27 g), followed by potassium carbonate (317 mg) at room temperature. After this mixture was stirred at room temperature for 1 hour, the mixture was filtered through a Celite pad. The filtrate was concentrated and the resulting residue was purified by a flash column chromatography (hexane:ethyl acetate=2:1) to give the desired product (10.1 g, 94%) as amorphous. the mixture was filtered through a Celite pad The filtrate was concentrated the resulting residue was purified by a flash column chromatography (hexane:ethyl acetate=2:1)

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

Procedure: To a solution of 20% sodium ethoxide-ethanol solution (34.0 g) diluted with ethanol (40 ml) was added a solution of diethyl malonate (16.0 g) in ethanol (40 ml) dropwise over 30 minutes in ice-cooling. After stirring in ice-cooling for additional 30 minutes, thereto was added 2-chloroacetamide (4.7 g) in one portion and the mixture was stirred in ice-cooling for 30 minutes and then at room temperature for 20 hours. The white solid precipitated was collected by filtering and washed with a small amount of ethanol. This white solid was dissolved in water (300 ml) and this resulting aqueous solution was acidified with conc. hydrochloric acid and extracted with dichloromethane (50 ml) three times. The extract was dried over magnesium sulfate, filtered and concentrated to give a yellow oil. This was purified by a flash column chromatography (n-hexane:ethyl acetate=2:1→1:1) to give ethyl 2,5-dioxopyrrolidine-3-carboxylate (5.63 g, 66%). cooling cooling for additional 30 minutes the mixture was stirred in ice- cooling for 30 minutes The white solid precipitated was collected by filtering washed with a small amount of ethanol This white solid was dissolved in water (300 ml) extracted with dichloromethane (50 ml) three times The extract was dried over magnesium sulfate filtered concentrated to give a yellow oil This was purified by a flash column chromatography (n-hexane:ethyl acetate=2:1→1:1)

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

Procedure: A mixture of 3.43 g (10 mmoles) of 3-octadecyloxy-2-aminopropanol synthesized according to the method of J. Hajdu et al. [J. Org. Chem., 48, 1197-1202 (1983)] and 1.73 g (10 mmoles) of carboethoxysuccinimide in 50 ml of dichloromethane was stirred, and 1.01 g of triethylamine was added to the mixture under ice-cooling. The resulting mixture was stirred at room temperature for 30 hours and concentrated to dryness. The residue was purified by silica gel chromatography to give 894 mg of the desired 2-succinimidopropane derivative. synthesized cooling concentrated to dryness The residue was purified by silica gel chromatography