methyl N-[(2S)-1-hydroxypropan-2-yl]carbamate

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

Procedure: To a solution of Intermediate (S)-methyl 1-hydroxypropan-2-ylcarbamate (2.65 g, 20 mmol) and triethylamine (7.0 ml, 50 mmol) in anhydrous dichloromethane (100 mL) was added methanesulfonyl chloride (1.91 mL, 23.9 mmol). The mixture was stirred at rt for 3 h and was then extracted with ethyl acetate. The organic layer was washed with 1N sodium hydroxide solution and brine, and was then dried over sodium sulfate, filtered and concentrated. The crude mesylate product was then dissolved in dry DMF (70 mL) and sodium azide (5.2 g, 80 mmol) was added. The mixture was heated with stirring at 80° C. for 2 h. The cooled reaction mixture was concentrated and the residue was partitioned between ethyl acetate and brine. The organic layer was separated and washed with brine, dried over sodium sulfate, filtered and concentrated. The residue was purified by silica gel chromatography (8:1 hexane/ethyl acetate eluant) to afford (S)-methyl 1-azidopropan-2-ylcarbamate. MS m/z 159.1 (M+1). was then extracted with ethyl acetate The organic layer was washed with 1N sodium hydroxide solution and brine was then dried over sodium sulfate filtered concentrated The crude mesylate product was then dissolved in dry DMF (70 mL) The mixture was heated with stirring at 80° C. for 2 h The cooled reaction mixture was concentrated the residue was partitioned between ethyl acetate and brine The organic layer was separated washed with brine dried over sodium sulfate filtered concentrated The residue was purified by silica gel chromatography (8:1 hexane/ethyl acetate eluant)

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

Procedure: To a solution of Intermediate (S)-methyl 1-hydroxypropan-2-ylcarbamate (2.65 g, 20 mmol) and triethylamine (7.0 ml, 50 mmol) in anhydrous dichloromethane (100 mL) was added methanesulfonyl chloride (1.91 mL, 23.9 mmol). The mixture was stirred at rt for 3 h and was then extracted with ethyl acetate. The organic layer was washed with 1N sodium hydroxide solution and brine, and was then dried over sodium sulfate, filtered and concentrated. The crude mesylate product was then dissolved in dry DMF (70 mL) and sodium azide (5.2 g, 80 mmol) was added. The mixture was heated with stirring at 80° C. for 2 h. The cooled reaction mixture was concentrated and the residue was partitioned between ethyl acetate and brine. The organic layer was separated and washed with brine, dried over sodium sulfate, filtered and concentrated. The residue was purified by silica gel chromatography (8:1 hexane/ethyl acetate eluant) to afford (S)-methyl 1-azidopropan-2-ylcarbamate. MS m/z 159.1(M+1). was then extracted with ethyl acetate The organic layer was washed with 1N sodium hydroxide solution and brine was then dried over sodium sulfate filtered concentrated The crude mesylate product was then dissolved in dry DMF (70 mL) The mixture was heated with stirring at 80° C. for 2 h The cooled reaction mixture was concentrated the residue was partitioned between ethyl acetate and brine The organic layer was separated washed with brine dried over sodium sulfate filtered concentrated The residue was purified by silica gel chromatography (8:1 hexane/ethyl acetate eluant)

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

Procedure: To a solution of (S)-alaninol (10 g, 130 mmol) and sodium bicarbonate (32.8 g, 390 mmol) in THF-H2O (1:1, 650 mL) at 0° C. was added dropwise methyl chloroformate (11.4 mL, 143 mmol). The mixture was stirred and allowed to warm to rt over 4 h, and was then extracted with ethyl acetate. The organic layer was washed with 1N aqueous sodium hydroxide solution and brine, and was then dried over sodium sulfate, filtered and concentrated to give the crude title compound, which was used without further purification. MS m/z 134.1 (M+1). was then extracted with ethyl acetate The organic layer was washed with 1N aqueous sodium hydroxide solution and brine was then dried over sodium sulfate filtered concentrated

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

Procedure: To a solution of Intermediate (S)-methyl 1-hydroxypropan-2-ylcarbamate (2.65 g, 20 mmol) and triethylamine (7.0 ml, 50 mmol) in anhydrous dichloromethane (100 mL) was added methanesulfonyl chloride (1.91 mL, 23.9 mmol). The mixture was stirred at rt for 3 h and was then extracted with ethyl acetate. The organic layer was washed with 1N sodium hydroxide solution and brine, and was then dried over sodium sulfate, filtered and concentrated. The crude mesylate product was then dissolved in dry DMF (70 mL) and sodium azide (5.2 g, 80 mmol) was added. The mixture was heated with stirring at 80° C. for 2 h. The cooled reaction mixture was concentrated and the residue was partitioned between ethyl acetate and brine. The organic layer was separated and washed with brine, dried over sodium sulfate, filtered and concentrated. The residue was purified by silica gel chromatography (8:1 hexane/ethyl acetate eluant) to afford (S)-methyl 1-azidopropan-2-ylcarbamate. MS m/z 159.1 (M+1). was then extracted with ethyl acetate The organic layer was washed with 1N sodium hydroxide solution and brine was then dried over sodium sulfate filtered concentrated The crude mesylate product was then dissolved in dry DMF (70 mL) The mixture was heated with stirring at 80° C. for 2 h The cooled reaction mixture was concentrated the residue was partitioned between ethyl acetate and brine The organic layer was separated washed with brine dried over sodium sulfate filtered concentrated The residue was purified by silica gel chromatography (8:1 hexane/ethyl acetate eluant)