ethyl 2-[(2-aminoacetyl)amino]acetate;hydrochloride

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

Procedure: To a solution of 289.4mg (1.47 mmol) of glycyl-glycine ethyl ester hydrochloride in anhydrous tetrahydrofuran (5 mL), 155.9 mg(1.54 mmol) of triethylamine, 451.5 mg (1.47 mmol) of N-t-butoxycarbonyl-β-cyclohexyl-L-alanine dihydrate, 205.3 mg (1.52 mmol) of 1-hydroxybenzotriazole hydrate, and 292.7 mg (1.53 mmol) of 1-[3-(dimethylaminomethyl)propyl]-3-ethylcarbodiimide hydrochloride were added sequentially with stirring under ice cooling. After the mixture was stirred for 1 hour, the reaction mixture was stirred at room temperature for 0.5 hour. The reaction mixture was concentrated under reduced pressure, chloroform (30 mL) was added to the residues, and the solution was washed sequentially with 0.5M hydrochloric acid (3×5 mL), water (3×5 mL) and 5% aqueous sodium hydrogencarbonate solution (3 ×5 mL). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure , whereby 570 mg of a crude product was obtained. The crude product was purified by column chromatography on alumina (alumina 2 g, chloroform), to give 552.8 mg of N-t-butoxycarbonyl-β-cyclohexyl-L-alanyl-glycyl-glycine ethyl ester (yield 91%) as a colorless crystalline powder. After the mixture was stirred for 1 hour the reaction mixture was stirred at room temperature for 0.5 hour The reaction mixture was concentrated under reduced pressure, chloroform (30 mL) was added to the residues the solution was washed sequentially with 0.5M hydrochloric acid (3×5 mL), water (3×5 mL) and 5% aqueous sodium hydrogencarbonate solution (3 ×5 mL) The organic layer was dried over anhydrous sodium sulfate concentrated under reduced pressure whereby 570 mg of a crude product was obtained The crude product was purified by column chromatography on alumina (alumina 2 g, chloroform)

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

Procedure: To a solution of 289.4mg (1.47 mmol) of glycyl-glycine ethyl ester hydrochloride in anhydrous tetrahydrofuran (5 mL), 155.9 mg(1.54 mmol) of triethylamine, 451.5 mg (1.47 mmol) of N-t-butoxycarbonyl-β-cyclohexyl-L-alanine dihydrate, 205.3 mg (1.52 mmol) of 1-hydroxybenzotriazole hydrate, and 292.7 mg (1.53 mmol) of 1-[3-(dimethylaminomethyl)propyl]-3-ethylcarbodiimide hydrochloride were added sequentially with stirring under ice cooling. After the mixture was stirred for 1 hour, the reaction mixture was stirred at room temperature for 0.5 hour. The reaction mixture was concentrated under reduced pressure, chloroform (30 mL) was added to the residues, and the solution was washed sequentially with 0.5M hydrochloric acid (3×5 mL), water (3×5 mL) and 5% aqueous sodium hydrogencarbonate solution (3 ×5 mL). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure , whereby 570 mg of a crude product was obtained. The crude product was purified by column chromatography on alumina (alumina 2 g, chloroform), to give 552.8 mg of N-t-butoxycarbonyl-β-cyclohexyl-L-alanyl-glycyl-glycine ethyl ester (yield 91%) as a colorless crystalline powder. After the mixture was stirred for 1 hour the reaction mixture was stirred at room temperature for 0.5 hour The reaction mixture was concentrated under reduced pressure, chloroform (30 mL) was added to the residues the solution was washed sequentially with 0.5M hydrochloric acid (3×5 mL), water (3×5 mL) and 5% aqueous sodium hydrogencarbonate solution (3 ×5 mL) The organic layer was dried over anhydrous sodium sulfate concentrated under reduced pressure whereby 570 mg of a crude product was obtained The crude product was purified by column chromatography on alumina (alumina 2 g, chloroform)

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

Procedure: To a solution of 289.4 mg (1.47 mmol) of glycyl-glycine ethyl ester hydrochloride in anhydrous tetrahydrofuran (5 mL), 155.9 mg (1.54 mmol) of triethylamine, 451.5 mg (1.47 mmol) of N-t-butoxycarbonyl-β-cyclohexyl-L-alanine dihydrate, 205.3 mg (1.52 mmol) of 1-hydroxybenzotriazole hydrate, and 292.7 mg (1.53 mmol) of 1-[3-(dimethylaminomethyl)propyl]-3-ethylcarbodiimide hydrochloride were added sequentially with stirring under ice cooling. After the mixture was stirred for 1 hour, the reaction mixture was stirred at room temperature for 0.5 hour. The reaction mixture was concentrated under reduced pressure, chloroform (30 mL) was added to the residues, and the solution was washed sequentially with 0.5M hydrochloric acid (3×5 mL), water (3×5 mL) and 5% aqueous sodiumhydrogen carbonate solution (3×5 mL). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure, whereby 570 mg of a crude product was obtained. The crude product was purified by column chromatography on alumina (alumina 2g, chloroform), to give 552.8 mg of N-t-butoxycarbonyl-β-cyclohexyl-L-alanyl-glycyl-glycine ethyl ester (yield 91%) as a colorless crystalline powder. After the mixture was stirred for 1 hour the reaction mixture was stirred at room temperature for 0.5 hour The reaction mixture was concentrated under reduced pressure, chloroform (30 mL) was added to the residues the solution was washed sequentially with 0.5M hydrochloric acid (3×5 mL), water (3×5 mL) and 5% aqueous sodiumhydrogen carbonate solution (3×5 mL) The organic layer was dried over anhydrous sodium sulfate concentrated under reduced pressure whereby 570 mg of a crude product was obtained The crude product was purified by column chromatography on alumina (alumina 2g, chloroform)

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

Procedure: To a solution of 289.4mg (1.47 mmol) of glycyl-glycine ethyl ester hydrochloride in anhydrous tetrahydrofuran (5 mL), 155.9 mg(1.54 mmol) of triethylamine, 451.5 mg (1.47 mmol) of N-t-butoxycarbonyl-β-cyclohexyl-L-alanine dihydrate, 205.3 mg (1.52 mmol) of 1-hydroxybenzotriazole hydrate, and 292.7 mg (1.53 mmol) of 1-[3-(dimethylaminomethyl)propyl]-3-ethylcarbodiimide hydrochloride were added sequentially with stirring under ice cooling. After the mixture was stirred for 1 hour, the reaction mixture was stirred at room temperature for 0.5 hour. The reaction mixture was concentrated under reduced pressure, chloroform (30 mL) was added to the residues, and the solution was washed sequentially with 0.5M hydrochloric acid (3×5 mL), water (3×5 mL) and 5% aqueous sodium hydrogencarbonate solution (3 ×5 mL). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure , whereby 570 mg of a crude product was obtained. The crude product was purified by column chromatography on alumina (alumina 2 g, chloroform), to give 552.8 mg of N-t-butoxycarbonyl-β-cyclohexyl-L-alanyl-glycyl-glycine ethyl ester (yield 91%) as a colorless crystalline powder. After the mixture was stirred for 1 hour the reaction mixture was stirred at room temperature for 0.5 hour The reaction mixture was concentrated under reduced pressure, chloroform (30 mL) was added to the residues the solution was washed sequentially with 0.5M hydrochloric acid (3×5 mL), water (3×5 mL) and 5% aqueous sodium hydrogencarbonate solution (3 ×5 mL) The organic layer was dried over anhydrous sodium sulfate concentrated under reduced pressure whereby 570 mg of a crude product was obtained The crude product was purified by column chromatography on alumina (alumina 2 g, chloroform)

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

Procedure: To a solution of 289.4 mg (1.47 mmol) of glycyl-glycine ethyl ester hydrochloride in anhydrous tetrahydrofuran (5 mL), 155.9 mg (1.54 mmol) of triethylamine, 451.5 mg (1.47 mmol) of N-t-butoxycarbonyl-β-cyclohexyl-L-alanine dihydrate, 205.3 mg (1.52 mmol) of 1-hydroxybenzotriazole hydrate, and 292.7 mg (1.53 mmol) of 1-[3-(dimethylaminomethyl)propyl]-3-ethylcarbodiimide hydrochloride were added sequentially with stirring under ice cooling. After the mixture was stirred for 1 hour, the reaction mixture was stirred at room temperature for 0.5 hour. The reaction mixture was concentrated under reduced pressure, chloroform (30 mL) was added to the residues, and the solution was washed sequentially with 0.5M hydrochloric acid (3×5 mL), water (3×5 mL) and 5% aqueous sodiumhydrogen carbonate solution (3×5 mL). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure, whereby 570 mg of a crude product was obtained. The crude product was purified by column chromatography on alumina (alumina 2g, chloroform), to give 552.8 mg of N-t-butoxycarbonyl-β-cyclohexyl-L-alanyl-glycyl-glycine ethyl ester (yield 91%) as a colorless crystalline powder. After the mixture was stirred for 1 hour the reaction mixture was stirred at room temperature for 0.5 hour The reaction mixture was concentrated under reduced pressure, chloroform (30 mL) was added to the residues the solution was washed sequentially with 0.5M hydrochloric acid (3×5 mL), water (3×5 mL) and 5% aqueous sodiumhydrogen carbonate solution (3×5 mL) The organic layer was dried over anhydrous sodium sulfate concentrated under reduced pressure whereby 570 mg of a crude product was obtained The crude product was purified by column chromatography on alumina (alumina 2g, chloroform)