methyl 3-amino-2-[(2-methylpropan-2-yl)oxycarbonylamino]benzoate

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

Procedure: Methyl 3-amino-2[(tert-butoxycarbonyl)amino]benzoate (61.8 g, 232 mmol) was added to trifluoroacetic acid (250 mL), and the mixture was stirred at room temperature for 3 hr. Trifluoroacetic acid was evaporated in vacuo, and the resulting solid was suspended in ethyl acetate (200 mL), collected by filtration and washed with ethyl acetate (50 mL). The solid was partitioned between ethyl acetate (300 mL) and saturated aqueous sodium hydrogen carbonate (400 mL), and the aqueous layer was seated and extracted with ethyl acetate (300 mL). The combined organic layer was washed with water (300 mL×2) and concentrated in vacuo to give the title compound (24.6 g, 148 mmol, 64%) as a brown solid. The filtrate described above was concentrated in vacuo, and the resulting solid was collected by filtration and washed with ethyl acetate. The filtrate was concentrated in vacuo, and the resulting solid was collected by filtration and washed with diethyl ether. The combined solid was partitioned between ethyl acetate (100 mL) and saturated aqueous sodium hydrogen carbonate (100 mL), and the aqueous layer was seated and extracted with ethyl acetate). The combined organic layer was washed with water and brine, dried over anhydrous sodium sulfate and concentrated in vacuo to give the title compound (8.29 g, 49.9 mmol, 22%) as a brown solid. Total amount: 32.9 g, 198 mmol, 85%. Trifluoroacetic acid was evaporated in vacuo collected by filtration washed with ethyl acetate (50 mL) The solid was partitioned between ethyl acetate (300 mL) and saturated aqueous sodium hydrogen carbonate (400 mL) extracted with ethyl acetate (300 mL) The combined organic layer was washed with water (300 mL×2) concentrated in vacuo

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

Procedure: To a suspension of methyl 2-[(tert-butoxycarbonyl)amino]-3-nitrobenzoate (103 g, 348 mmol) in methanol (800 mL) was added 10% palladium on carbon (50% wet; 10 g), and the mixture was purged with hydrogen and stirred under balloon pressure hydrogen at room temperature for 5 hr. The catalyst was removed by filtration, and the filtrate was concentrated in vacuo. The residual solid was suspended in diisopropyl ether (300 mL), and the suspension was stirred at room temperature for 3 hr. The resulting solid was collected by filtration and washed with diisopropyl ether to give the title compound (42.0 g, 158 mmol, 45%). The mixture of the removed catalyst described above and a colorless solid (the title compound) was suspended in tetrahydrofuran (200 mL), and the suspension was stirred at room temperature for 30 minutes. The insoluble material (the catalyst) was removed by filtration, and the filtrate was concentrated in vacuo. The residual solid was suspended in diisopropyl ether (300 mL), and the suspension was refluxed for 30 min. The resulting solid was collected by filtration and washed with diisopropyl ether to give the title compound (33.9 g, 127 mmol, 36%) as a colorless solid. Total amount: 75.9 g, 285 mmol, 82%. the mixture was purged with hydrogen The catalyst was removed by filtration the filtrate was concentrated in vacuo the suspension was stirred at room temperature for 3 hr The resulting solid was collected by filtration washed with diisopropyl ether

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

Procedure: Methyl 3-amino-2-[(tert-butoxycarbonyl)amino]benzoate (61.8 g, 232 mmol) was added to trifluoroacetic acid (250 mL), and the mixture was stirred at room temperature for 3 hr. Trifluoroacetic acid was evaporated in vacuo, and the resulting solid was suspended in ethyl acetate (200 mL), collected by filtration and washed with ethyl acetate (50 mL). The solid was partitioned between ethyl acetate (300 mL) and saturated aqueous sodium hydrogen carbonate (400 mL), and the aqueous layer was separated and extracted with ethyl acetate (300 mL). The combined organic layer was washed with water (300 mL×2) and concentrated in vacuo to give the title compound (24.6 g, 148 mmol, 64%) as a brown solid. The filtrate described above was concentrated in vacuo, and the resulting solid was collected by filtration and washed with ethyl acetate. The filtrate was concentrated in vacuo, and the resulting solid was collected by filtration and washed with diethyl ether. The combined solid was partitioned between ethyl acetate (100 mL) and saturated aqueous sodium hydrogen carbonate (100 mL), and the aqueous layer was separated and extracted with ethyl, acetate). The combined organic layer was washed with water and brine, dried over anhydrous sodium sulfate and concentrated in vacuo to give the title compound (8.29 g, 49.9 mmol, 22%) as a brown solid. Total amount: 32.9 g, 198 mmol, 85%. Trifluoroacetic acid was evaporated in vacuo collected by filtration washed with ethyl acetate (50 mL) The solid was partitioned between ethyl acetate (300 mL) and saturated aqueous sodium hydrogen carbonate (400 mL) the aqueous layer was separated extracted with ethyl acetate (300 mL) The combined organic layer was washed with water (300 mL×2) concentrated in vacuo

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

Procedure: To a suspension of methyl 2-[(tert-butoxycarbonyl)amino]-3-nitrobenzoate (103 g, 0.348 mmol) in methanol (800 mL) was added 10% palladium on carbon (50% wet; 10 g), and the mixture was purged with hydrogen and stirred under balloon pressure hydrogen at room temperature for 5 hr. The catalyst was removed by filtration, and the filtrate was concentrated in vacuo. The residual solid was suspended in diisopropyl ether (300 mL), and the suspension was stirred at room temperature for 3 hr. The resulting solid was collected by filtration and washed with diisopropyl ether to give the title compound (42.0 g, 158 mmol, 45%). The mixture of the removed catalyst described above and a colorless solid (the title compound) was suspended in tetrahydrofuran (200 mL), and the suspension was stirred at room temperature for 30 minutes. The insoluble material (the catalyst) was removed by filtration, and the filtrate was concentrated in vacuo. The residual solid was suspended in diisopropyl ether (300 mL), and the suspension was refluxed for 30 min. The resulting solid was collected by filtration and washed with diisopropyl ether to give the title compound (33.9 g, 127 mmol, 36%) as a colorless solid. Total amount: 75.9 g, 285 mmol, 82%. the mixture was purged with hydrogen The catalyst was removed by filtration the filtrate was concentrated in vacuo the suspension was stirred at room temperature for 3 hr The resulting solid was collected by filtration washed with diisopropyl ether