tert-butyl N-[(2R)-1-amino-1-oxopropan-2-yl]carbamate

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

Procedure: 2,4-Bis(4-methoxyphenyl)-2,4-dithioxo-1,3,2,4-dithiadiphosphetane (1.6 g, 0.0038 mol) was added to a solution of tert-butyl[(1R)-2-amino-1-methyl-2-oxoethyl]carbamate (1.45 g, 0.00770 mol) in 1,2-dimethoxyethane (40 mL). The resulting suspension was stirred at RT for 5 h. After removal of solvent the residue was taken up into ethyl acetate. It was washed with 0.1 N NaOH solution, water, brine; dried over Na2SO4. After filtration the filtrate was concentrated to yield 1.58 g of the product. (yield: ˜100%). After removal of solvent the residue It was washed with 0.1 N NaOH solution, water, brine dried over Na2SO4 After filtration the filtrate was concentrated

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

Procedure: 2,4-Bis(4-methoxyphenyl)-2,4-dithioxo-1,3,2,4-dithiadiphosphetane (1.6 g, 0.0038 mol) was added to a solution of tert-butyl[(1R)-2-amino-1-methyl-2-oxoethyl]carbamate (1.45 g, 0.00770 mol) in 1,2-dimethoxyethane (40 mL). The resulting suspension was stirred at RT for 5 h. After removal of solvent the residue was taken up into ethyl acetate. It was washed with 0.1 N NaOH solution, water, brine; dried over Na2SO4. After filtration the filtrate was concentrated to yield 1.58 g of the product. (yield: ˜100%). After removal of solvent the residue It was washed with 0.1 N NaOH solution, water, brine dried over Na2SO4 After filtration the filtrate was concentrated

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

Procedure: 2,4-Bis(4-methoxyphenyl)-2,4-dithioxo-1,3,2,4-dithiadiphosphetane (1.6 g, 0.0038 mol) was added to a solution of tert-butyl [(1R)-2-amino-1-methyl-2-oxoethyl]carbamate (1.45 g, 0.00770 mol) in 1,2-dimethoxyethane (40 mL). The resulting suspension was stirred at RT for 5 h. After removal of solvent the residue was taken up into ethyl acetate. It was washed with 0.1 N NaOH solution, water, brine; dried over Na2SO4. After filtration the filtrate was concentrated to yield 1.58 g of the product. (yield: ˜100%). After removal of solvent the residue It was washed with 0.1 N NaOH solution, water, brine dried over Na2SO4 After filtration the filtrate was concentrated

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

Procedure: 2,4-Bis(4-methoxyphenyl)-2,4-dithioxo-1,3,2,4-dithiadiphosphetane (1.6 g, 0.0038 mol) was added to a solution of tert-butyl[(1R)-2-amino-1-methyl-2-oxoethyl]carbamate (1.45 g, 0.00770 mol) in 1,2-dimethoxyethane (40 mL). The resulting suspension was stirred at RT for 5 h. After removal of solvent the residue was taken up into ethyl acetate. It was washed with 0.1 N NaOH solution, water, brine; dried over Na2SO4. After filtration the filtrate was concentrated to yield 1.58 g of the product. (yield: ˜100%). After removal of solvent the residue It was washed with 0.1 N NaOH solution, water, brine dried over Na2SO4 After filtration the filtrate was concentrated

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

Procedure: 2,4-Bis(4-methoxyphenyl)-2,4-dithioxo-1,3,2,4-dithiadiphosphetane (1.6 g, 0.0038 mol) was added to a solution of tert-butyl [(1R)-2-amino-1-methyl-2-oxoethyl]carbamate (1.45 g, 0.00770 mol) in 1,2-dimethoxyethane (40 mL). The resulting suspension was stirred at RT for 5 h. After removal of solvent the residue was taken up into ethyl acetate. It was washed with 0.1 N NaOH solution, water, brine; dried over Na2SO4. After filtration the filtrate was concentrated to yield 1.58 g of the product. (yield: ˜100%). After removal of solvent the residue It was washed with 0.1 N NaOH solution, water, brine dried over Na2SO4 After filtration the filtrate was concentrated

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

Procedure: 2,4-Bis(4-methoxyphenyl)-2,4-dithioxo-1,3,2,4-dithiadiphosphetane (1.6 g, 0.0038 mol) was added to a solution of tert-butyl [(1R)-2-amino-1-methyl-2-oxoethyl]carbamate (1.45 g, 0.00770 mol) in 1,2-dimethoxyethane (40 mL). The resulting suspension was stirred at RT for 5 h. After removal of solvent the residue was taken up into ethyl acetate. It was washed with 0.1 N NaOH solution, water, brine; dried over Na2SO4. After filtration the filtrate was concentrated to yield 1.58 g of the product. (yield: ˜100%). After removal of solvent the residue It was washed with 0.1 N NaOH solution, water, brine dried over Na2SO4 After filtration the filtrate was concentrated

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

Procedure: To a solution of (R)-tert-butyl 1-amino-1-oxopropan-2-ylcarbamate (Int-X-A, 1 g, 5.31 mmol) and 4-methylbenzene-1-sulfonyl chloride (4.05 g, 21.25 mmol) in CH2Cl2 (5 mL) was added pyridine (2.101 g, 26.6 mmol). After 3 h, acetic anhydride (0.651 g, 6.38 mmol) was added. This was stirred overnight before it was concentrated and EtOAc was added. Saturated NaHCO3 was added and the two phase mixture was stirred vigorously for 2 h. The organic layer was washed with 1 N HCl and then saturated NaHCO3. The organic layer was dried and concentrated. The resulting residue was purified by flash chromatography (Isco Combiflash Companion, 40 g silica gel, 15% ethyl acetate-hexane) to provide the product (R)-tert-butyl 1-cyanoethylcarbamate (Int-X-B, 336 mg, 1.974 mmol, 37.2% yield); [M+Na]+=193.2; 1H NMR (400 MHz, methanol-d4) δ ppm 4.51 (1 H, q), 1.34-1.58 (12 H, m). was concentrated EtOAc was added Saturated NaHCO3 was added the two phase mixture was stirred vigorously for 2 h The organic layer was washed with 1 N HCl The organic layer was dried concentrated The resulting residue was purified by flash chromatography (Isco Combiflash Companion, 40 g silica gel, 15% ethyl acetate-hexane)

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

Procedure: (R)-2-(tert-Butoxycarbonylamino)propanoic acid (1 g, 5.29 mmol), EDC (1.216 g, 6.34 mmol), and HOBt (0.971 g, 6.34 mmol) were dissolved in CH2Cl2 (5 mL). Ammonia (0.5 M) in dioxane (52.9 mL, 26.4 mmol) and 4-methylmorpholine (3.49 mL, 31.7 mmol) were added to the reaction mixture. After stirring for 1 h, the solvent was removed and ethyl acetate was added. This was washed with brine and saturated NaHCO3 solution. The organic layer was dried and concentrated to provide the product (R)-tert-butyl 1-amino-1-oxopropan-2-ylcarbamate (Int-X-A, 229 mg, 1.217 mmol, 23.02% yield); [M+Na]+=211.2; 1H NMR (400 MHz, methanol-d4) δ ppm 4.06 (1 H, q), 1.44 (9 H, s), 1.31 (3 H, d, J=7.04 Hz). the solvent was removed ethyl acetate was added This was washed with brine and saturated NaHCO3 solution The organic layer was dried concentrated

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

Procedure: 2,4-Bis(4-methoxyphenyl)-2,4-dithioxo-1,3,2,4-dithiadiphosphetane (1.6 g, 0.0038 mol) was added to a solution of tert-butyl [(1R)-2-amino-1-methyl-2-oxoethyl]carbamate (1.45 g, 0.00770 mol) in 1,2-dimethoxyethane (40 mL). The resulting suspension was stirred at RT for 5 h. After removal of solvent the residue was taken up into ethyl acetate. It was washed with 0.1 N NaOH solution, water, brine; dried over Na2SO4. After filtration the filtrate was concentrated to yield 1.58 g of the product. (yield: ˜100%). After removal of solvent the residue It was washed with 0.1 N NaOH solution, water, brine dried over Na2SO4 After filtration the filtrate was concentrated