tert-butyl N-[(2S)-1-amino-4-methyl-1-oxopentan-2-yl]carbamate

Conditions: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of (S)-tert-butyl 1-amino-4-methyl-1-oxopentan-2-ylcarbamate (1.8 g, 8 mmol) and Lawesson's reagent (1.58 g, 4 mmol) in toluene (20 mL) was stirred at 90° C. for 2.5 h. After removal of the solvent under reduced pressure, the residue was purified by column chromatography (silica gel, 30 g, ethyl acetate/MeOH, 20/1) to yield the title compound (1.38 g, 72%) as yellow solid; MS: m/e 269.2 [M+H]+. After removal of the solvent under reduced pressure the residue was purified by column chromatography (silica gel, 30 g, ethyl acetate/MeOH, 20/1)

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

Procedure: A mixture of (S)-2-(tert-butoxycarbonylamino)-4-methylpentanoic acid (1.8 g), di-tert-butyl dicarbonate (CAN:24424-99-5, 12 mmol) and pyridine (3 mL) in CH3CN (50 mL) was stirred at room temperature for 20 min. Ammonium hydroxide solution (25%-28% NH3, 15 mL) was added dropwise during 30 min. The resulting reaction mixture was stirred overnight. During the removal of solvents, the product precipitated, was collected by filtration and dried to give the target compound as a white solid (1.55 g, 86%). MS (D): m/e=253.2 [M+Na]+. The resulting reaction mixture was stirred overnight During the removal of solvents the product precipitated was collected by filtration dried

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

Procedure: A mixture of (S)-2-(tert-butoxycarbonylamino)-4-methylpentanoic acid (1.8 g), di-tert-butyl dicarbonate (CAN:24424-99-5, 12 mmol) and pyridine (3 mL) in CH3CN (50 mL) was stirred at room temperature for 20 min. Ammonium hydroxide solution (25%-28% NH3, 15 mL) was added dropwise during 30 min. The resulting reaction mixture was stirred overnight. During the removal of solvents, the product precipitated, was collected by filtration and dried to give the target compound as a white solid (1.55 g, 86%). MS (D): m/e=253.2 [M+Na]+. The resulting reaction mixture was stirred overnight During the removal of solvents the product precipitated was collected by filtration dried

Conditions: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of (S)-tert-butyl 1-amino-4-methyl-1-oxopentan-2-ylcarbamate (1.8 g, 8 mmol) and Lawesson's reagent (1.58 g, 4 mmol) in toluene (20 mL) was stirred at 90° C. for 2.5 h. After removal of the solvent under reduced pressure, the residue was purified by column chromatography (silica gel, 30 g, ethyl acetate/MeOH, 20/1) to yield the title compound (1.38 g, 72%) as yellow solid; MS: m/e 269.2 [M+H]+. After removal of the solvent under reduced pressure the residue was purified by column chromatography (silica gel, 30 g, ethyl acetate/MeOH, 20/1)

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

Procedure: A mixture of (S)-2-(tert-butoxycarbonylamino)-4-methylpentanoic acid (1.8 g), di-tert-butyl dicarbonate (CAN:24424-99-5, 12 mmol) and pyridine (3 mL) in CH3CN (50 mL) was stirred at room temperature for 20 min. Ammonium hydroxide solution (25%-28% NH3, 15 mL) was added dropwise during 30 min. The resulting reaction mixture was stirred overnight. During the removal of solvents, the product precipitated, was collected by filtration and dried to give the target compound as a white solid (1.55 g, 86%). MS (D): m/e=253.2 [M+Na]+. The resulting reaction mixture was stirred overnight During the removal of solvents the product precipitated was collected by filtration dried

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

Procedure: A mixture of (S)-2-(tert-butoxycarbonylamino)-4-methylpentanoic acid (1.8 g), di-tert-butyl dicarbonate (CAN:24424-99-5, 12 mmol) and pyridine (3 mL) in CH3CN (50 mL) was stirred at room temperature for 20 min. Ammonium hydroxide solution (25%-28% NH3, 15 mL) was added dropwise during 30 min. The resulting reaction mixture was stirred overnight. During the removal of solvents, the product precipitated, was collected by filtration and dried to give the target compound as a white solid (1.55 g, 86%). MS (D): m/e=253.2 [M+Na]+. The resulting reaction mixture was stirred overnight During the removal of solvents the product precipitated was collected by filtration dried

Conditions: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of (S)-tert-butyl 1-amino-4-methyl-1-oxopentan-2-ylcarbamate (1.8 g, 8 mmol) and Lawesson's reagent (1.58 g, 4 mmol) in toluene (20 mL) was stirred at 90° C. for 2.5 h. After removal of the solvent under reduced pressure, the residue was purified by column chromatography (silica gel, 30 g, ethyl acetate/MeOH, 20/1) to yield the title compound (1.38 g, 72%) as yellow solid; MS: m/e 269.2 [M+H]+. After removal of the solvent under reduced pressure the residue was purified by column chromatography (silica gel, 30 g, ethyl acetate/MeOH, 20/1)

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

Procedure: A mixture of (S)-2-(tert-butoxycarbonylamino)-4-methylpentanoic acid (1.8 g), di-tert-butyl dicarbonate (CAN:24424-99-5, 12 mmol) and pyridine (3 mL) in CH3CN (50 mL) was stirred at room temperature for 20 min. Ammonium hydroxide solution (25%-28% NH3, 15 mL) was added dropwise during 30 min. The resulting reaction mixture was stirred overnight. During the removal of solvents, the product precipitated, was collected by filtration and dried to give the target compound as a white solid (1.55 g, 86%). MS (D): m/e=253.2 [M+Na]+. The resulting reaction mixture was stirred overnight During the removal of solvents the product precipitated was collected by filtration dried

Conditions: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of (S)-tert-butyl 1-amino-4-methyl-1-oxopentan-2-ylcarbamate (1.8 g, 8 mmol) and Lawesson's reagent (1.58 g, 4 mmol) in toluene (20 mL) was stirred at 90° C. for 2.5 h. After removal of the solvent under reduced pressure, the residue was purified by column chromatography (silica gel, 30 g, ethyl acetate/MeOH, 20/1) to yield the title compound (1.38 g, 72%) as yellow solid; MS: m/e 269.2 [M+H]+. After removal of the solvent under reduced pressure the residue was purified by column chromatography (silica gel, 30 g, ethyl acetate/MeOH, 20/1)

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

Procedure: A mixture of (S)-2-(tert-butoxycarbonylamino)-4-methylpentanoic acid (1.8 g), di-tert-butyl dicarbonate (CAN:24424-99-5, 12 mmol) and pyridine (3 mL) in CH3CN (50 mL) was stirred at room temperature for 20 min. Ammonium hydroxide solution (25%-28% NH3, 15 mL) was added dropwise during 30 min. The resulting reaction mixture was stirred overnight. During the removal of solvents, the product precipitated, was collected by filtration and dried to give the target compound as a white solid (1.55 g, 86%). MS (D): m/e=253.2 [M+Na]+. The resulting reaction mixture was stirred overnight During the removal of solvents the product precipitated was collected by filtration dried