tert-butyl N-(1-amino-2-methyl-1-oxopropan-2-yl)carbamate

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

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

Procedure: N2-{[(1,1-dimethylethyl)oxy]carbonyl}-2-methylalaninamide (3.87 g, 19.13 mmol), Lawesson's reagent (7.74 g, 19.13 mmol) and tetrahydrofuran (THF) (100 mL) was heated to 50° C. for 3 hours. The reaction was concentrated, added 150 cc of EtOAc and washed with sat'd NaHCO3 (3×100 cc), water and brine. The EtOAc layer was concentrated and the residue was purified via chromatography on silica gel eluted Hex to 1:1 Hex/EtOAc to obtain the title compound (2.04 g, 48% yield). The reaction was concentrated added 150 cc of EtOAc washed with sat'd NaHCO3 (3×100 cc), water and brine The EtOAc layer was concentrated the residue was purified via chromatography on silica gel eluted Hex to 1:1 Hex/EtOAc

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

Procedure: To a solution of (1-carbamoyl-1-methyl-ethyl)-carbamic acid tert-butyl ester (945 mg, 4.67 mmol) in dichloromethane (20 mL) was added trifluoroacetic acid (10.0 mL, 64 mmol). The reaction mixture was stirred at room temperature for 4 h. The reaction mixture was then concentrated in vacuo to afford 882 mg of the title compound as a white solid, isolated as the TFA salt, m/z 103.2 [M+1]+. The reaction mixture was then concentrated in vacuo

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

Procedure: To a solution of tert-butyl 1-amino-2-methyl-1-oxopropan-2-ylcarbamate (Example 12 a, 12.5 g) and triethylamine (CAN 121-44-8, 29 g) in methylene chloride (150 mL) was added trifluoroacetic acid anhydride (CAN 407-25-0, 27.2 g) dropwise at 0° C. The resulting mixture was allowed to warm to room temperature and stirred for 4 h. After that the mixture was washed with water, 5 N citric acid and brine, the organic phase was dried over anhydrous sodium sulfate and concentrated to give the title compound (11 g, 97%) as a yellow solid; MS: m/e=207.1 [M+Na]+. After that the mixture was washed with water, 5 N citric acid and brine the organic phase was dried over anhydrous sodium sulfate concentrated

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

Procedure: To a mixture of tert-butyl 1-amino-2-methyl-1-oxopropan-2-ylcarbamate (10 g, 49 mmol) in toluene (200 mL) was added Lawesson's reagent (CAN 19172-47-5, 10 g, 25 mmol). The suspension was heated to 90° C. and stirred for 6 h. After evaporation of solvents, the residue was purified by column chromatography (silica gel, 120 g) eluting with 30% ethyl acetate in petroleum ether to yield the title compound (6 g, 56%); MS: m/e 241.2 [M+Na]+. After evaporation of solvents the residue was purified by column chromatography (silica gel, 120 g) eluting with 30% ethyl acetate in petroleum ether

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

Procedure: To a mixture of tert-butyl 1-amino-2-methyl-1-oxopropan-2-ylcarbamate (10 g, 49 mmol) in toluene (200 mL) was added Lawesson's reagent (CAN 19172-47-5, 10 g, 25 mmol). The suspension was heated to 90° C. and stirred for 6 h. After evaporation of solvents, the residue was purified by column chromatography (silica gel, 120 g) eluting with 30% ethyl acetate in petroleum ether to yield the title compound (6 g, 56%); MS: m/e 241.2 [M+Na]+. After evaporation of solvents the residue was purified by column chromatography (silica gel, 120 g) eluting with 30% ethyl acetate in petroleum ether

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

Procedure: A mixture of 2-(tert-butoxycarbonylamino)-2-methylpropanoic acid (CAN: 30992-29-1, 20 g, 98 mmol), di-tert-butyl dicarbonate (CAN 24424-99-5, 27.67 g, 147 mmol) and pyridine (4.6 mL) in acetonitrile (500 mL) was stirred at room temperature for 20 min. Ammonia (10 mL) was added dropwise for 20 min. The resulting reaction mixture was stirred for 4 h. After removal of most of the solvent under reduced pressure, the solid was filtered off and washed with acetonitrile. The solid was brought to dryness under reduced pressure to give the title compound (17.5 g, 88%) as white solid; MS (EI): m/e 225.1 [M+Na]+. The resulting reaction mixture was stirred for 4 h After removal of most of the solvent under reduced pressure the solid was filtered off washed with acetonitrile

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

Procedure: To a solution of tert-butyl 1-amino-2-methyl-1-oxopropan-2-ylcarbamate (Example 12 a, 12.5 g) and triethylamine (CAN 121-44-8, 29 g) in methylene chloride (150 mL) was added trifluoroacetic acid anhydride (CAN 407-25-0, 27.2 g) dropwise at 0° C. The resulting mixture was allowed to warm to room temperature and stirred for 4 h. After that the mixture was washed with water, 5 N citric acid and brine, the organic phase was dried over anhydrous sodium sulfate and concentrated to give the title compound (11 g, 97%) as a yellow solid; MS: m/e=207.1 [M+Na]+. After that the mixture was washed with water, 5 N citric acid and brine the organic phase was dried over anhydrous sodium sulfate concentrated

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

Procedure: To a solution of tert-butyl 1-amino-2-methyl-1-oxopropan-2-ylcarbamate (Example 12 a, 12.5 g) and triethylamine (CAN 121-44-8, 29 g) in methylene chloride (150 mL) was added trifluoroacetic acid anhydride (CAN 407-25-0, 27.2 g) dropwise at 0° C. The resulting mixture was allowed to warm to room temperature and stirred for 4 h. After that the mixture was washed with water, 5 N citric acid and brine, the organic phase was dried over anhydrous sodium sulfate and concentrated to give the title compound (11 g, 97%) as a yellow solid; MS: m/e=207.1 [M+Na]+. After that the mixture was washed with water, 5 N citric acid and brine the organic phase was dried over anhydrous sodium sulfate concentrated

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

Procedure: To a mixture of tert-butyl 1-amino-2-methyl-1-oxopropan-2-ylcarbamate (10 g, 49 mmol) in toluene (200 mL) was added Lawesson's reagent (CAN 19172-47-5, 10 g, 25 mmol). The suspension was heated to 90° C. and stirred for 6 h. After evaporation of solvents, the residue was purified by column chromatography (silica gel, 120 g) eluting with 30% ethyl acetate in petroleum ether to yield the title compound (6 g, 56%); MS: m/e 241.2 [M+Na]+. After evaporation of solvents the residue was purified by column chromatography (silica gel, 120 g) eluting with 30% ethyl acetate in petroleum ether

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

Procedure: A mixture of 2-(tert-butoxycarbonylamino)-2-methylpropanoic acid (CAN: 30992-29-1, 20 g, 98 mmol), di-tert-butyl dicarbonate (CAN 24424-99-5, 27.67 g, 147 mmol) and pyridine (4.6 mL) in acetonitrile (500 mL) was stirred at room temperature for 20 min. Ammonia (10 mL) was added dropwise for 20 min. The resulting reaction mixture was stirred for 4 h. After removal of most of the solvent under reduced pressure, the solid was filtered off and washed with acetonitrile. The solid was brought to dryness under reduced pressure to give the title compound (17.5 g, 88%) as white solid; MS (EI): m/e 225.1 [M+Na]+. The resulting reaction mixture was stirred for 4 h After removal of most of the solvent under reduced pressure the solid was filtered off washed with acetonitrile

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

Procedure: A mixture of 2-(tert-butoxycarbonylamino)-2-methylpropanoic acid (CAN: 30992-29-1, 20 g, 98 mmol), di-tert-butyl dicarbonate (CAN 24424-99-5, 27.67 g, 147 mmol) and pyridine (4.6 mL) in acetonitrile (500 mL) was stirred at room temperature for 20 min. Ammonia (10 mL) was added dropwise for 20 min. The resulting reaction mixture was stirred for 4 h. After removal of most of the solvent under reduced pressure, the solid was filtered off and washed with acetonitrile. The solid was brought to dryness under reduced pressure to give the title compound (17.5 g, 88%) as white solid; MS (EI): m/e 225.1 [M+Na]+. The resulting reaction mixture was stirred for 4 h After removal of most of the solvent under reduced pressure the solid was filtered off washed with acetonitrile