tert-butyl 4-amino-2-methoxybenzoate

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

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

Procedure: 3,5-Dichloro-4-ethoxybenzoic acid (4) (75 mg, 0.32 mmol) in DCM (5 mL) was treated with oxalyl chloride (56 μL, 0.64 mmol) dropwise, followed by a drop of DMF. The reaction mixture was stirred at RT for 1 h, and then the solvent was removed in vacuo. The residue was dissolved in DCM (5 mL) and TEA (133 μL, 957 μmol) was added. The mixture was added to tert-butyl 4-amino-2-methoxybenzoate (3) (71 mg, 0.32 mmol) and stirred at RT for 16 h. The mixture was sequentially washed with sat. aq. NaHCO3 (5 mL) and 1 M HCl (5 mL), and the organic phase was concentrated in vacuo. The residue was purified by silica gel chromatography (12 g, 0-100% EtOAc in isohexane) to afford tert-butyl 4-(3,5-dichloro-4-ethoxybenzamido)-2-methoxybenzoate (5) (59 mg, 42%) as a white solid: m/z 384 [M−tBu+2H]+ (ES+); 1H-NMR (400 MHz, DMSO-d6) δ: 10.51 (1H, s), 8.09 (2H, s), 7.63 (1H, d), 7.60 (1H, d), 7.43 (1H, dd), 4.15 (2H, q), 3.81 (3H, s), 1.51 (9H, s), 1.41 (3H, t). the solvent was removed in vacuo The residue was dissolved in DCM (5 mL) stirred at RT for 16 h The mixture was sequentially washed with sat. aq. NaHCO3 (5 mL) and 1 M HCl (5 mL) the organic phase was concentrated in vacuo The residue was purified by silica gel chromatography (12 g, 0-100% EtOAc in isohexane)

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

Procedure: tert-Butyl 2-methoxy-4-nitrobenzoate (2) (271 mg, 1.07 mmol) was dissolved in MeOH (270 mL) and passed through a Thales ‘H-cube’ cartridge (10% Pd/C) at a flow rate of 1 mL/min at 25° C. under full H2 mode. The solvent was removed in vacuo to afford tert-butyl 4-amino-2-methoxybenzoate (3) (234 mg, 92%) as a pale yellow solid: m/z 222 [M−H]− (ES−); 1H-NMR (400 MHz, DMSO-d6) δ: 7.41 (1H, d), 6.16 (1H, d), 6.09 (1H, dd), 5.82 (2H, br s), 3.68 (3H, s), 1.45 (9H, s). at 25° C. The solvent was removed in vacuo

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

Procedure: 3,5-Dichloro-4-ethoxybenzoic acid (4) (75 mg, 0.32 mmol) in DCM (5 mL) was treated with oxalyl chloride (56 μL, 0.64 mmol) dropwise, followed by a drop of DMF. The reaction mixture was stirred at RT for 1 h, and then the solvent was removed in vacuo. The residue was dissolved in DCM (5 mL) and TEA (133 μL, 957 μmol) was added. The mixture was added to tert-butyl 4-amino-2-methoxybenzoate (3) (71 mg, 0.32 mmol) and stirred at RT for 16 h. The mixture was sequentially washed with sat. aq. NaHCO3 (5 mL) and 1 M HCl (5 mL), and the organic phase was concentrated in vacuo. The residue was purified by silica gel chromatography (12 g, 0-100% EtOAc in isohexane) to afford tert-butyl 4-(3,5-dichloro-4-ethoxybenzamido)-2-methoxybenzoate (5) (59 mg, 42%) as a white solid: m/z 384 [M−tBu+2H]+ (ES+); 1H-NMR (400 MHz, DMSO-d6) δ: 10.51 (1H, s), 8.09 (2H, s), 7.63 (1H, d), 7.60 (1H, d), 7.43 (1H, dd), 4.15 (2H, q), 3.81 (3H, s), 1.51 (9H, s), 1.41 (3H, t). the solvent was removed in vacuo The residue was dissolved in DCM (5 mL) stirred at RT for 16 h The mixture was sequentially washed with sat. aq. NaHCO3 (5 mL) and 1 M HCl (5 mL) the organic phase was concentrated in vacuo The residue was purified by silica gel chromatography (12 g, 0-100% EtOAc in isohexane)

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

Procedure: tert-Butyl 2-methoxy-4-nitrobenzoate (2) (271 mg, 1.07 mmol) was dissolved in MeOH (270 mL) and passed through a Thales ‘H-cube’ cartridge (10% Pd/C) at a flow rate of 1 mL/min at 25° C. under full H2 mode. The solvent was removed in vacuo to afford tert-butyl 4-amino-2-methoxybenzoate (3) (234 mg, 92%) as a pale yellow solid: m/z 222 [M−H]− (ES−); 1H-NMR (400 MHz, DMSO-d6) δ: 7.41 (1H, d), 6.16 (1H, d), 6.09 (1H, dd), 5.82 (2H, br s), 3.68 (3H, s), 1.45 (9H, s). at 25° C. The solvent was removed in vacuo

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

Procedure: tert-Butyl 4-isocyanato-2-methoxy-benzoate was prepared from tert-butyl 4-amino-2-methoxy-benzoate and phosgene using the procedure of step 2 of Example 1.

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

Procedure: 3,5-Dichloro-4-ethoxybenzoic acid (4) (75 mg, 0.32 mmol) in DCM (5 mL) was treated with oxalyl chloride (56 μL, 0.64 mmol) dropwise, followed by a drop of DMF. The reaction mixture was stirred at RT for 1 h, and then the solvent was removed in vacuo. The residue was dissolved in DCM (5 mL) and TEA (133 μL, 957 μmol) was added. The mixture was added to tert-butyl 4-amino-2-methoxybenzoate (3) (71 mg, 0.32 mmol) and stirred at RT for 16 h. The mixture was sequentially washed with sat. aq. NaHCO3 (5 mL) and 1 M HCl (5 mL), and the organic phase was concentrated in vacuo. The residue was purified by silica gel chromatography (12 g, 0-100% EtOAc in isohexane) to afford tert-butyl 4-(3,5-dichloro-4-ethoxybenzamido)-2-methoxybenzoate (5) (59 mg, 42%) as a white solid: m/z 384 [M−tBu+2H]+ (ES+); 1H-NMR (400 MHz, DMSO-d6) δ: 10.51 (1H, s), 8.09 (2H, s), 7.63 (1H, d), 7.60 (1H, d), 7.43 (1H, dd), 4.15 (2H, q), 3.81 (3H, s), 1.51 (9H, s), 1.41 (3H, t). the solvent was removed in vacuo The residue was dissolved in DCM (5 mL) stirred at RT for 16 h The mixture was sequentially washed with sat. aq. NaHCO3 (5 mL) and 1 M HCl (5 mL) the organic phase was concentrated in vacuo The residue was purified by silica gel chromatography (12 g, 0-100% EtOAc in isohexane)

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

Procedure: tert-Butyl 2-methoxy-4-nitrobenzoate (2) (271 mg, 1.07 mmol) was dissolved in MeOH (270 mL) and passed through a Thales ‘H-cube’ cartridge (10% Pd/C) at a flow rate of 1 mL/min at 25° C. under full H2 mode. The solvent was removed in vacuo to afford tert-butyl 4-amino-2-methoxybenzoate (3) (234 mg, 92%) as a pale yellow solid: m/z 222 [M−H]− (ES−); 1H-NMR (400 MHz, DMSO-d6) δ: 7.41 (1H, d), 6.16 (1H, d), 6.09 (1H, dd), 5.82 (2H, br s), 3.68 (3H, s), 1.45 (9H, s). at 25° C. The solvent was removed in vacuo