ethyl N-amino-N-methylcarbamate

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

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 0.009 moles of t-butyloxycarbonylalanylalanylproline in 80 ml of dry tetrahydrofuran which has been cooled to -20° to -30° is added 1.0 ml of N-methylmorpholine and 1.2 ml of isobutylchloroformate. After stirring for 10 minutes there is added 0.009 moles of 2-azaalanine ethyl ester in 50 ml of chloroform. The reaction mixture is stirred overnight at room temperature and then concentrated in vacuo. The residue is taken up between ethyl acetate and 0.25 N hydrochloric acid. The organic layer is separated, washed with saturated sodium bicarbonate solution, water, dried over magnesium sulfate and concentrated in vacuo. The residue is chromatographed on silica gel. Elution with ethyl acetate gives t-butyloxycarbonylalanylalanylprolyl-2-azaalanine ethyl ester. The reaction mixture is stirred overnight at room temperature concentrated in vacuo The organic layer is separated washed with saturated sodium bicarbonate solution, water dried over magnesium sulfate concentrated in vacuo The residue is chromatographed on silica gel Elution with ethyl acetate

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

Procedure: To a solution of 0.009 moles of t-butyloxycarbonylalanylalanylproline in 80 ml of dry tetrahydrofuran which has been cooled to -20° to -30° is added 1.0 ml of N-methylmorpholine and 1.2 ml of isobutylchloroformate. After stirring for 10 minutes there is added 0.009 moles of 2-azaalanine ethyl ester in 50 ml of chloroform. The reaction mixture is stirred overnight at room temperature and then concentrated in vacuo. The residue is taken up between ethyl acetate and 0.25 N hydrochloric acid. The organic layer is separated, washed with saturated sodium bicarbonate solution, water, dried over magnesium sulfate and concentrated in vacuo. The residue is chromatographed on silica gel. Elution with ethyl acetate gives t-butyloxycarbonylalanylalanylprolyl-2-azaalanine ethyl ester. The reaction mixture is stirred overnight at room temperature concentrated in vacuo The organic layer is separated washed with saturated sodium bicarbonate solution, water dried over magnesium sulfate concentrated in vacuo The residue is chromatographed on silica gel Elution with ethyl acetate

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

Procedure: To 0.16 mole of t-butoxycarbonylalanylproline in 80 ml of dry tetrahydrofuran which has been cooled to -20° to -30° is added 2 ml of N-methylmorpholine and then 2.1 ml of isobutylchloroformate. After stirring for 10 minutes, 0.16 mole of 2-azaalanine ethyl ester and 60 ml of chloroform are added. The reaction mixture is allowed to warm to room temperature overnight, concentrated in vacuo, taken up in ethyl acetate and the insoluble material removed by filtration. Concentration of the filtrate in vacuo gives t-butoxycarbonylalanylprolyl-2-azaalanine ethyl ester. concentrated in vacuo the insoluble material removed by filtration

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

Procedure: To a stirred solution of acetylalanylalanylproline (2 mmole) and N-methylmorpholine (2 mmole) in dry tetrahydrofuran (20 ml) at -20° to -25° C. is added isobutyl chloroformate (2 mmole). After 5 minutes a solution of 2-azaalanine ethyl ester (2 mmole) in tetrahydrofuran (3 ml) is added dropwise and the reaction mixture is allowed to warm to room temperature over a period of 1 hour and stirred for a further 4 hours. The precipitate is filtered off and the filtrate is evaporated to dryness. Chromatography on silica gel (50 gm) and elution with 10% methanol in chloroform gives pure acetylalanylalanylprolyl-2-azaalanine ethyl ester. The precipitate is filtered off the filtrate is evaporated to dryness Chromatography on silica gel (50 gm) and elution with 10% methanol in chloroform

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 0.009 moles of t-butyloxycarbonylalanylalanylproline in 80 ml of dry tetrahydrofuran which has been cooled to -20° to -30° is added 1.0 ml of N-methylmorpholine and 1.2 ml of isobutylchloroformate. After stirring for 10 minutes there is added 0.009 moles of 2-azaalanine ethyl ester in 50 ml of chloroform. The reaction mixture is stirred overnight at room temperature and then concentrated in vacuo. The residue is taken up between ethyl acetate and 0.25 N hydrochloric acid. The organic layer is separated, washed with saturated sodium bicarbonate solution, water, dried over magnesium sulfate and concentrated in vacuo. The residue is chromatographed on silica gel. Elution with ethyl acetate gives t-butyloxycarbonylalanylalanylprolyl-2-azaalanine ethyl ester. The reaction mixture is stirred overnight at room temperature concentrated in vacuo The organic layer is separated washed with saturated sodium bicarbonate solution, water dried over magnesium sulfate concentrated in vacuo The residue is chromatographed on silica gel Elution with ethyl acetate

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

Procedure: To 0.16 mole of t-butoxycarbonylalanylproline in 80 ml of dry tetrahydrofuran which has been cooled to -20° to -30° is added 2 ml of N-methylmorpholine and then 2.1 ml of isobutylchloroformate. After stirring for 10 minutes, 0.16 mole of 2-azaalanine ethyl ester and 60 ml of chloroform are added. The reaction mixture is allowed to warm to room temperature overnight, concentrated in vacuo, taken up in ethyl acetate and the insoluble material removed by filtration. Concentration of the filtrate in vacuo gives t-butoxycarbonylalanylprolyl-2-azaalanine ethyl ester. concentrated in vacuo the insoluble material removed by filtration

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

Procedure: To a stirred solution of acetylalanylalanylproline (2 mmole) and N-methylmorpholine (2 mmole) in dry tetrahydrofuran (20 ml) at -20° to -25° C. is added isobutyl chloroformate (2 mmole). After 5 minutes a solution of 2-azaalanine ethyl ester (2 mmole) in tetrahydrofuran (3 ml) is added dropwise and the reaction mixture is allowed to warm to room temperature over a period of 1 hour and stirred for a further 4 hours. The precipitate is filtered off and the filtrate is evaporated to dryness. Chromatography on silica gel (50 gm) and elution with 10% methanol in chloroform gives pure acetylalanylalanylprolyl-2-azaalanine ethyl ester. The precipitate is filtered off the filtrate is evaporated to dryness Chromatography on silica gel (50 gm) and elution with 10% methanol in chloroform

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