tert-butyl 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:

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

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: (2R)-2-(N-tert-Butoxycarbonyl-N-methylamino)-3-(2-fluorophenyl)propionic acid as a dicyclohexylammonium salt (5.57 g; 18.73 mmol) was dissolved in methylene chloride (30 mL) and washed with an aqueous solution of sodium hydrogen sulfate (10%; 30 mL). The organic phase was dried (magnesium sulfate) and filtered. 1-Hydroxybenzotriazole hydrate (2.53 g; 18.73 mmol) and N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (3.75 g; 19.6 mmol) were added to the filtrate and the mixture was stirred for 15 min at room temperature. Methylamine (40% in methanol; 0.53 g; 17.0 mmol) and diisopropylethylamine (3.2 mL; 18.7 mmol) were added and the reaction mixture was stirred for 12 hours at room temperature. The reaction mixture was washed with an aqueous solution of sodium hydrogen carbonate (50 mL) and an aqueous solution of sodium hydrogen sulfate (10%; 50 mL) and dried (magnesium sulfate). The solvent was removed in vacuo and the residue was chromatographed on silica (3.5×40 cm) using ethyl acetate/heptane (2:1) as eluent to afford 2.4 g of N-((1R)-2-(2-Fluorophenyl)-1-methylcarbamoyl)ethyl)-N-methylcarbamic acid tert-butyl ester. washed with an aqueous solution of sodium hydrogen sulfate (10%; 30 mL) The organic phase was dried (magnesium sulfate) filtered the reaction mixture was stirred for 12 hours at room temperature The reaction mixture was washed with an aqueous solution of sodium hydrogen carbonate (50 mL) an aqueous solution of sodium hydrogen sulfate (10%; 50 mL) and dried (magnesium sulfate) The solvent was removed in vacuo the residue was chromatographed on silica (3.5×40 cm)

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: A solution of methyl-carbamic acid t-butyl ester (5.0 g, 38.0 mmol) in DMF (50 mL) was chilled in an ice bath, and NaH (60%, 1.7 g, 41.8 mmol) was added in portions at 10C. The mixture was stirred for an additional 30 minutes. A solution of 3-bromomethyl-phthalic acid dimethyl ester (10.9 g, 38.0 mmol) in DMF (20 mL) was slowly added, keeping the temperature at 10-15° C. The resulting mixture was stirred at room temperature overnight. The mixture was poured into ice water (400 mL) and extracted with EtOAc (4×70 mL). The combined EtOAc extracts were washed with water (3×50 mL) and brine (50 mL), and dried (MgSO4). The solvent was removed in vacuo, and the residue was purified by flash chromatography (SiO2, Hexane:EtOAc 8:2) to give 3-[(t-butoxycarbonyl-methyl-amino)-methyl]-phthalic dimethyl ester (7.7 g, 60%) as an oil: 1H NMR (CDCl3) δ 7.93-7.89 (m, 1H), 7.49-7.46 (m, 2H), 4.46 (s, 2H), 3.94 (s, 3H), 3.89 (s, 3H), 2.87-2.76 (b, 3H), 1.49-1.42 (b, 9H). at 10-15° C The resulting mixture was stirred at room temperature overnight extracted with EtOAc (4×70 mL) The combined EtOAc extracts were washed with water (3×50 mL) and brine (50 mL) dried (MgSO4) The solvent was removed in vacuo the residue was purified by flash chromatography (SiO2, Hexane:EtOAc 8:2)

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

Procedure: A solution of methyl-carbamic acid t-butyl ester (5.0 g, 38.0 mmol) in DMF (50 mL) was chilled in an ice bath, and NaH (60%, 1.7 g, 41.8 mmol) was added in portions at 10C. The mixture was stirred for an additional 30 minutes. A solution of 3-bromomethyl-phthalic acid dimethyl ester (10.9 g, 38.0 mmol) in DMF (20 mL) was slowly added, keeping the temperature at 10-15° C. The resulting mixture was stirred at room temperature overnight. The mixture was poured into ice water (400 mL) and extracted with EtOAc (4×70 mL). The combined EtOAc extracts were washed with water (3×50 mL) and brine (50 mL), and dried (MgSO4). The solvent was removed in vacuo, and the residue was purified by flash chromatography (SiO2, Hexane:EtOAc 8:2) to give 3-[(t-butoxycarbonyl-methyl-amino)-methyl]-phthalic dimethyl ester (7.7 g, 60%) as an oil: 1H NMR (CDCl3) δ 7.93-7.89 (m, 1H), 7.49-7.46 (m, 2H), 4.46 (s, 2H), 3.94 (s, 3H), 3.89 (s, 3H), 2.87-2.76 (b, 3H), 1.49-1.42 (b, 9H). at 10-15° C The resulting mixture was stirred at room temperature overnight extracted with EtOAc (4×70 mL) The combined EtOAc extracts were washed with water (3×50 mL) and brine (50 mL) dried (MgSO4) The solvent was removed in vacuo the residue was purified by flash chromatography (SiO2, Hexane:EtOAc 8:2)

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 4-fluoro-phenyl)-((S)-5-pyrrolidin-2-yl-pyridin-3-yl)-methanone (2.57 g, 9.5 mmole) and (S)-[(S)-2-(tert-butoxycarbonyl-methyl-amino)-propionylamino]-cyclohexyl-acetic acid (5) (3.58 g, 10.5 mmole) in 75 mL of THF at 0° C., is added 4-(4,6-dimethoxy-[1,3,5]triazin-2-yl)-4-methyl-morpholinium chloride hydrate (2.97 g, 10.7 mmole) in one portion. After stirring at 20° C. for 2 hours, the reaction mixture is diluted with 100 mL of EtOAc, and washed with 3×20 mL of water. After concentration, the crude product is purified by flash column chromatography (CH2Cl2 95%, MeOH 5%) to give (S)-1-((S)-1-cyclohexyl-2-{(S)-2-[5-(4-fluoro-benzoyl)-pyridin-3-yl]pyrrolidin-1-yl}-2-oxo-ethylcarbamoyl)-ethyl]-methyl-carbamic acid tert-butyl ester (6) (5.0 g, yield 88%) as pale yellow solid. washed with 3×20 mL of water After concentration the crude product is purified by flash column chromatography (CH2Cl2 95%, MeOH 5%)