ethyl 5-[(2-methylpropan-2-yl)oxycarbonylamino]-3-oxopentanoate

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

Procedure: A stirred solution of anhydrous sodium acetate (2.05 g, 25 mmol) in water (12.5 ml) was added with the solution of 5-tert-butoxycarbonylamino-3-oxo-pentanoic acid ethyl ester (3.23 g, 12.5 mmol) in anhydrous ethanol (2 ml), then the mixture was added with 2-amino-1-(4-fluoro-phenyl)-ethanone hydrochloride (2.37 g, 12.5 mmol), heated to reflux for 3 hours. The resulting mixture was extracted with ethyl acetate (50 ml×3) and the combined extracts were washed with brine (50 ml×3), dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give 2-(2-tert-butoxycarbonylamino-ethyl)-4-(4-fluoro-phenyl)-1H-pyrrole-3-carboxylic acid ethyl ester (4.3 g, 91.7%) as a yellow solid. heated to reflux for 3 hours The resulting mixture was extracted with ethyl acetate (50 ml×3) the combined extracts were washed with brine (50 ml×3) dried with anhydrous sodium sulfate filtered concentrated under reduced pressure

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

Procedure: A stirred solution of [3-(2,2-dimethyl-4,6-dioxo-[1,3]dioxan-5-ylidene)-3-hydroxy-propyl]-carbamic acid tert-butyl ester (18.75 g, 50 mmol) in absolute ethanol (112 ml) was heated overnight at 70° C. The mixture was concentrated under reduced pressure to give 5-tert-butoxycarbonylamino-3-oxo-pentanoic acid ethyl ester (14 g, 98%) as a yellow oil which was used as such. The mixture was concentrated under reduced pressure

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

Procedure: A stirred solution of anhydrous sodium acetate (2.66 g, 82 mmol) in 140 ml of water was added with the solution of 5-tert-butoxycarbonylamino-3-oxo-pentanoic acid ethyl ester (4.20 g, 16.2 mmol) in 20 ml of absolute ethanol at room temperature. Upon completion of the addition, the mixture was stirred for 5 minutes, added with 2-amino-1-phenyl-ethanone (2.5 g, 14.6 mmol) and heated to reflux for 3 hours. The resulting mixture was added with water (300 ml), extracted with ethyl acetate (100 ml×3). The organic extracts were washed with brine (50 ml×3), dried with anhydrous sodium sulfate, filtered and concentrated to give 2-(2-tert-butoxycarbonylamino-ethyl)-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester (5.0 g, 88.7%). Upon completion of the addition heated to reflux for 3 hours extracted with ethyl acetate (100 ml×3) The organic extracts were washed with brine (50 ml×3) dried with anhydrous sodium sulfate filtered concentrated

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

Procedure: A stirred solution of anhydrous sodium acetate (2.66 g, 82 mmol) in 140 ml of water was added with the solution of 5-tert-butoxycarbonylamino-3-oxo-pentanoic acid ethyl ester (4.20 g, 16.2 mmol) in 20 ml of absolute ethanol at room temperature. Upon completion of the addition, the mixture was stirred for 5 minutes, added with 2-amino-1-phenyl-ethanone (2.5 g, 14.6 mmol) and heated to reflux for 3 hours. The resulting mixture was added with water (300 ml), extracted with ethyl acetate (100 ml×3). The organic extracts were washed with brine (50 ml×3), dried with anhydrous sodium sulfate, filtered and concentrated to give 2-(2-tert-butoxycarbonylamino-ethyl)-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester (5.0 g, 88.7%). Upon completion of the addition heated to reflux for 3 hours extracted with ethyl acetate (100 ml×3) The organic extracts were washed with brine (50 ml×3) dried with anhydrous sodium sulfate filtered concentrated

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A stirred solution of [3-(2,2-dimethyl-4,6-dioxo-[1,3]dioxin-5-ylidene)-3-hydroxy-propyl]-carbamic acid tert-butyl ester in absolute ethanol (112 ml) was heated to reflux at 70° C. overnight, and cooled to room temperature. The mixture was filtered and concentrated under reduced pressure to give 5-tert-butoxycarbonylamino-3-oxo-pentanoic acid ethyl ester (11.22 g, 87%) as a white solid. cooled to room temperature The mixture was filtered concentrated under reduced pressure

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

Procedure: A stirred solution of anhydrous sodium acetate (2.05 g, 25 mmol) in water (12.5 ml) was added with the solution of 5-tert-butoxycarbonylamino-3-oxo-pentanoic acid ethyl ester (3.23 g, 12.5 mmol) in anhydrous ethanol (2 ml), then the mixture was added with 2-amino-1-(4-fluoro-phenyl)-ethanone hydrochloride (2.37 g, 12.5 mmol), heated to reflux for 3 hours. The resulting mixture was extracted with ethyl acetate (50 ml×3) and the combined extracts were washed with brine (50 ml×3), dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give 2-(2-tert-butoxycarbonylamino-ethyl)-4-(4-fluoro-phenyl)-1H-pyrrole-3-carboxylic acid ethyl ester (4.3 g, 91.7%) as a yellow solid. heated to reflux for 3 hours The resulting mixture was extracted with ethyl acetate (50 ml×3) the combined extracts were washed with brine (50 ml×3) dried with anhydrous sodium sulfate filtered concentrated under reduced pressure

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

Procedure: A stirred solution of [3-(2,2-dimethyl-4,6-dioxo-[1,3]dioxan-5-ylidene)-3-hydroxy-propyl]-carbamic acid tert-butyl ester (18.75 g, 50 mmol) in absolute ethanol (112 ml) was heated overnight at 70° C. The mixture was concentrated under reduced pressure to give 5-tert-butoxycarbonylamino-3-oxo-pentanoic acid ethyl ester (14 g, 98%) as a yellow oil which was used as such. The mixture was concentrated under reduced pressure

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

Procedure: A stirred solution of anhydrous sodium acetate (2.05 g, 25 mmol) in water (12.5 ml) was added with the solution of 5-tert-butoxycarbonylamino-3-oxo-pentanoic acid ethyl ester (3.23 g, 12.5 mmol) in anhydrous ethanol (2 ml), then the mixture was added with 2-amino-1-(4-fluoro-phenyl)-ethanone hydrochloride (2.37 g, 12.5 mmol), heated to reflux for 3 hours. The resulting mixture was extracted with ethyl acetate (50 ml×3) and the combined extracts were washed with brine (50 ml×3), dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give 2-(2-tert-butoxycarbonylamino-ethyl)-4-(4-fluoro-phenyl)-1H-pyrrole-3-carboxylic acid ethyl ester (4.3 g, 91.7%) as a yellow solid. heated to reflux for 3 hours The resulting mixture was extracted with ethyl acetate (50 ml×3) the combined extracts were washed with brine (50 ml×3) dried with anhydrous sodium sulfate filtered concentrated under reduced pressure

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

Procedure: A stirred solution of anhydrous sodium acetate (2.05 g, 25 mmol) in water (12.5 ml) was added with the solution of 5-tert-butoxycarbonylamino-3-oxo-pentanoic acid ethyl ester (3.23 g, 12.5 mmol) in anhydrous ethanol (2 ml), then the mixture was added with 2-amino-1-(4-fluoro-phenyl)-ethanone hydrochloride (2.37 g, 12.5 mmol), heated to reflux for 3 hours. The resulting mixture was extracted with ethyl acetate (50 ml×3) and the combined extracts were washed with brine (50 ml×3), dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give 2-(2-tert-butoxycarbonylamino-ethyl)-4-(4-fluoro-phenyl)-1H-pyrrole-3-carboxylic acid ethyl ester (4.3 g, 91.7%) as a yellow solid. heated to reflux for 3 hours The resulting mixture was extracted with ethyl acetate (50 ml×3) the combined extracts were washed with brine (50 ml×3) dried with anhydrous sodium sulfate filtered concentrated under reduced pressure

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

Procedure: A stirred solution of anhydrous sodium acetate (2.66 g, 82 mmol) in 140 ml of water was added with the solution of 5-tert-butoxycarbonylamino-3-oxo-pentanoic acid ethyl ester (4.20 g, 16.2 mmol) in 20 ml of absolute ethanol at room temperature. Upon completion of the addition, the mixture was stirred for 5 minutes, added with 2-amino-1-phenyl-ethanone (2.5 g, 14.6 mmol) and heated to reflux for 3 hours. The resulting mixture was added with water (300 ml), extracted with ethyl acetate (100 ml×3). The organic extracts were washed with brine (50 ml×3), dried with anhydrous sodium sulfate, filtered and concentrated to give 2-(2-tert-butoxycarbonylamino-ethyl)-4-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester (5.0 g, 88.7%). Upon completion of the addition heated to reflux for 3 hours extracted with ethyl acetate (100 ml×3) The organic extracts were washed with brine (50 ml×3) dried with anhydrous sodium sulfate filtered concentrated

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A stirred solution of [3-(2,2-dimethyl-4,6-dioxo-[1,3]dioxin-5-ylidene)-3-hydroxy-propyl]-carbamic acid tert-butyl ester in absolute ethanol (112 ml) was heated to reflux at 70° C. overnight, and cooled to room temperature. The mixture was filtered and concentrated under reduced pressure to give 5-tert-butoxycarbonylamino-3-oxo-pentanoic acid ethyl ester (11.22 g, 87%) as a white solid. cooled to room temperature The mixture was filtered concentrated under reduced pressure

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A stirred solution of [3-(2,2-dimethyl-4,6-dioxo-[1,3]dioxin-5-ylidene)-3-hydroxy-propyl]-carbamic acid tert-butyl ester in absolute ethanol (112 ml) was heated to reflux at 70° C. overnight, and cooled to room temperature. The mixture was filtered and concentrated under reduced pressure to give 5-tert-butoxycarbonylamino-3-oxo-pentanoic acid ethyl ester (11.22 g, 87%) as a white solid. cooled to room temperature The mixture was filtered concentrated under reduced pressure