methyl (2R)-2-amino-3-methylsulfanylpropanoate

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

Procedure: To a solution of 0.96 g N-(morpholinocarbonyl)-L-phenylalanine 3 and 0.55 g S-methyl-L-cysteine methyl ester in 50 mL anhydrous methylene chloride at ambient temperature was added 0.50 mL triethylamine, 0.51 g 1-hydroxybenzotriazole and 0.70 g 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride. After being stirred for 4 h, the solution was diluted with 100 mL ethyl acetate and was washed with 2×35 mL 0.1N hydrochloric acid solution and 2×35 mL 0.1N sodium hydroxide solution. The organic phase was dried over magnesium sulfate, filtered and concentrated in vacuo to afford 1.15 g of the desired solid dipeptide. was washed with 2×35 mL 0.1N hydrochloric acid solution and 2×35 mL 0.1N sodium hydroxide solution The organic phase was dried over magnesium sulfate filtered concentrated in vacuo

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

Procedure: To a solution of 0.96 g N-(morpholinocarbonyl)-L-phenylalanine 3 and 0.55 g S-methyl-L-cysteine methyl ester in 50 mL anhydrous methylene chloride at ambient temperature was added 0.50 mL triethylamine, 0.51 g 1-hydroxybenzotriazole and 0.70 g 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride. After being stirred for 4 h, the solution was diluted with 100 mL ethyl acetate and was washed with 2×35 mL 0.1N hydrochloric acid solution and 2×35 mL 0.1N sodium hydroxide solution. The organic phase was dried over magnesium sulfate, filtered and concentrated in vacuo to afford 1.15 g of the desired solid dipeptide. was washed with 2×35 mL 0.1N hydrochloric acid solution and 2×35 mL 0.1N sodium hydroxide solution The organic phase was dried over magnesium sulfate filtered concentrated in vacuo

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

Procedure: In analogy to Example 2, but using only one mole equivalent of triethylamine, 5 g (27 mmol) of (-)-S-methyl-L-cysteine methyl ester were reacted with 3.51 g (22.5 mmol) of 2-chloro-3-nitropyridine (reaction conditions: 5 hours at 80° C.). Working up was followed by chromatography on silica gel (n-heptane/acetone/methyl t-butyl ether=5:1:1). 3.3 g (45%) of N-(3-nitro-2-pyridyl)-(-)-S-methyl-L-cysteine methyl ester, of melting point 95°-97° C., were obtained.

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

Procedure: In analogy to Example 2, but using only one mole equivalent of triethylamine, 5 g (27 mmol) of (-)-S-methyl-L-cysteine methyl ester were reacted with 3.51 g (22.5 mmol) of 2-chloro-3-nitropyridine (reaction conditions: 5 hours at 80° C.). Working up was followed by chromatography on silica gel (n-heptane/acetone/methyl t-butyl ether=5:1:1). 3.3 g (45%) of N-(3-nitro-2-pyridyl)-(-)-S-methyl-L-cysteine methyl ester, of melting point 95°-97° C., were obtained.

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

Procedure: To a solution of 0.96 g N-(morpholinocarbonyl)-L-phenylalanine 3 and 0.55 g S-methyl-L-cysteine methyl ester in 50 mL anhydrous methylene chloride at ambient temperature was added 0.50 mL triethylamine, 0.51 g 1-hydroxybenzotriazole and 0.70 g 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride. After being stirred for 4 h, the solution was diluted with 100 mL ethyl acetate and was washed with 2×35 mL 0.1N hydrochloric acid solution and 2×35 mL 0.1N sodium hydroxide solution. The organic phase was dried over magnesium sulfate, filtered and concentrated in vacuo to afford 1.15 g of the desired solid dipeptide. was washed with 2×35 mL 0.1N hydrochloric acid solution and 2×35 mL 0.1N sodium hydroxide solution The organic phase was dried over magnesium sulfate filtered concentrated in vacuo

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

Procedure: To a solution of 0.96 g N-(morpholinocarbonyl)-L-phenylalanine 3 and 0.55 g S-methyl-L-cysteine methyl ester in 50 mL anhydrous methylene chloride at ambient temperature was added 0.50 mL triethylamine, 0.51 g 1-hydroxybenzotrazole and 0.70 g 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride. After being stirred for 4 h, the solution was diluted with 100 mL ethyl acetate and was washed with 2×35 mL 0.1N hydrochloric acid solution and 2×35 mL 0.1N sodium hydroxide solution. The organic phase was dried over magnesium sulfate, filtered and concentrated in vacuo to afford 1.15 g of the desired solid dipeptide. was washed with 2×35 mL 0.1N hydrochloric acid solution and 2×35 mL 0.1N sodium hydroxide solution The organic phase was dried over magnesium sulfate filtered concentrated in vacuo

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

Procedure: To a solution of 0.96 g N-(morpholinocarbonyl)-L-phenylalanine 3 and 0.55 g S-methyl-L-cysteine methyl ester in 50 mL anhydrous methylene chloride at ambient temperature was added 0.50 mL triethylamine, 0.51 g 1-hydroxybenzotriazole and 0.70 g 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride. After being stirred for 4 h, the solution was diluted with 100 mL ethyl acetate and was washed with 2×35 mL 0.1N hydrochloric acid solution and 2×35 mL 0.1N sodium hydroxide solution. The organic phase was dried over magnesium sulfate, filtered and concentrated in vacuo to afford 1.15 g of the desired solid dipeptide. was washed with 2×35 mL 0.1N hydrochloric acid solution and 2×35 mL 0.1N sodium hydroxide solution The organic phase was dried over magnesium sulfate filtered concentrated in vacuo

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

Procedure: In analogy to Example 2, but using only one mole equivalent of triethylamine, 5 g (27 mmol) of (-)-S-methyl-L-cysteine methyl ester were reacted with 3.51 g (22.5 mmol) of 2-chloro-3-nitropyridine (reaction conditions: 5 hours at 80° C.). Working up was followed by chromatography on silica gel (n-heptane/acetone/methyl t-butyl ether=5:1:1). 3.3 g (45%) of N-(3-nitro-2-pyridyl)-(-)-S-methyl-L-cysteine methyl ester, of melting point 95°-97° C., were obtained.