ethyl 2-(4-amino-2-chlorophenyl)acetate

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

Procedure: To a solution of ethyl 2-(4-amino-2-chlorophenyl)acetate (240 mg, 1.12 mmol) in dry dichloromethane (4 mL), was added triethylamine (3.13 mL, 22.47 mmol) followed by triphosgene (333 mg, 1.12 mmol) solution in dichloromethane (1 mL). The reaction mixture was stirred at room temperature for 1 h. To this mixture was then added 3-(tetrahydrofuran-3-yloxy)aniline (403 mg, 2.25 mmol) in dichloromethane (1 mL). The reaction mixture was stirred at room temperature for 4 h and concentrated. The residue was dissolved in ethyl acetate and washed with water (2×20 mL), brine (10 mL), dried and concentrated. The crude product was purified by flash column chromatography to afford the desired product as a clear oil (221 mg, 0.528 mmol, 47%). 1H NMR: 1.30 (t, 3H, J=7.2 Hz), 2.05-2.15 (m, 2H), 3.68 (s, 2H), 3.81-3.97 (m, 4H), 4.21 (q, 2H, J=7.2 Hz), 4.82 (d, 1H, J=1.6 Hz), 6.49 (dd, 1H, J=8 Hz, 1.6 Hz), 6.71 (d, 1H, J=7.6 Hz), 7.02-7.11 (m, 4H), 7.18 (s, 1H), 7.53 (s, 1H), 7.59 (s, 1H). The reaction mixture was stirred at room temperature for 4 h concentrated The residue was dissolved in ethyl acetate washed with water (2×20 mL), brine (10 mL) dried concentrated The crude product was purified by flash column chromatography

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

Procedure: To a solution of ethyl 2-(4-amino-2-chlorophenyl)acetate (178 mg, 0.833 mmol) in dry dichloromethane (5 mL), was added triethylamine (2.32 mL, 16.66 mmol) followed by triphosgene (247 mg, 0.833 mmol) solution in dichloromethane (1 mL). The reaction mixture was stirred at room temperature for 1 h. To this mixture was then added tert-butyl 2-aminocyclohexylcarbamate (357 mg, 1.67 mmol) in dichloromethane (1 mL). The reaction mixture was stirred at room temperature for 4 h and concentrated. The residue was dissolved in ethyl acetate and washed with water (2×20 mL), brine (10 mL), dried and concentrated. The crude product was purified by flash column chromatography to afford the desired product as a mixture of cis and trans diastereomers (220 mg, 0.485 mmol, 58%). 1H NMR: 1.23-1.28 (m, 6H), 1.38 (s, 9H), 1.70-1.73 (m, 2H), 2.01-2.08 (m, 2H), 3.29-3.32 (m, 1H), 3.53-3.58 (m, 1H), 3.68 (s, 2H), 4.11-4.19 (m, 2H), 5.01 (d, 1H, J=8.8 Hz), 5.57 (d, 1H, J=8 Hz), 7.13 (d, 1H, J=8.4 Hz), 7.20 (d, 1H, J=6.8 Hz), 7.41 (s, 1H), 7.46 (s, 1H). The reaction mixture was stirred at room temperature for 4 h concentrated The residue was dissolved in ethyl acetate washed with water (2×20 mL), brine (10 mL) dried concentrated The crude product was purified by flash column chromatography

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

Procedure: To a solution of ethyl 2-(4-amino-2-chlorophenyl)acetate (178 mg, 0.833 mmol) in dry dichloromethane (5 mL), was added triethylamine (2.32 mL, 16.66 mmol) followed by triphosgene (247 mg, 0.833 mmol) solution in dichloromethane (1 mL). The reaction mixture was stirred at room temperature for 1 h. To this mixture was then added tert-butyl 2-aminocyclohexylcarbamate (357 mg, 1.67 mmol) in dichloromethane (1 mL). The reaction mixture was stirred at room temperature for 4 h and concentrated. The residue was dissolved in ethyl acetate and washed with water (2×20 mL), brine (10 mL), dried and concentrated. The crude product was purified by flash column chromatography to afford the desired product as a mixture of cis and trans diastereomers (220 mg, 0.485 mmol, 58%). 1H NMR: 1.23-1.28 (m, 6H), 1.38 (s, 9H), 1.70-1.73 (m, 2H), 2.01-2.08 (m, 2H), 3.29-3.32 (m, 1H), 3.53-3.58 (m, 1H), 3.68 (s, 2H), 4.11-4.19 (m, 2H), 5.01 (d, 1H, J=8.8 Hz), 5.57 (d, 1H, J=8 Hz), 7.13 (d, 1H, J=8.4 Hz), 7.20 (d, 1H, J=6.8 Hz), 7.41 (s, 1H), 7.46 (s, 1H). The reaction mixture was stirred at room temperature for 4 h concentrated The residue was dissolved in ethyl acetate washed with water (2×20 mL), brine (10 mL) dried concentrated The crude product was purified by flash column chromatography

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

Procedure: A mixture of 0.600 g of 2-chloro-3-nitro-pyridine (Aldrich) and 0.800 g of (4-amino-2-chloro-phenyl)-acetic acid ethyl ester (see WO 97/21665) in 20 ml of EtOH/dioxane (1:1, v/v) is stirred and refluxed for 72 hours. The mixture obtained is allowed to cool to rt and is concentrated in vacuo. The concentrate obtained is subjected to silica gel column chromatography. A solid is obtained which is triturated with Et2O. [2-Chloro-4-(3-nitro-pyridin-2-ylamino)-phenyl]-acetic acid ethyl ester is obtained in the form of a solid. ES-MS: 336.0 [M+H]+; single peak at tR=5.59 min (System 1); Rf=0.39 (Hexane/EtOAc, 7:3). refluxed for 72 hours The mixture obtained is concentrated in vacuo The concentrate obtained A solid is obtained which is triturated with Et2O

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

Procedure: A mixture of 2-chloro-3-nitro-pyridine (0.600 g, 3.80 mmol) (Aldrich) and (4-amino-2-chloro-phenyl)-acetic acid ethyl ester (see WO 97/21665) (0.800 g 3.80 mmol) in EtOH/dioxane (20 mL; 1:1, v/v) is stirred and refluxed for 72 h. The mixture is allowed to cool to rt and concentrated in vacuo. The crude material is purified by silica gel column chromatography (Hexane/EtOAc, 7/3) to afford a red solid, which upon trituration with Et2O provides the title compound as an orange solid: ES-MS: 336.0 [M+H]+; single peak at tR=5.59 min (System 1); Rf=0.39 (Hexane/EtOAc, 7:3). refluxed for 72 h concentrated in vacuo The crude material is purified by silica gel column chromatography (Hexane/EtOAc, 7/3) to afford a red solid, which upon trituration with Et2O

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

Procedure: To a solution of ethyl 2-(4-amino-2-chlorophenyl)acetate (240 mg, 1.12 mmol) in dry dichloromethane (4 mL), was added triethylamine (3.13 mL, 22.47 mmol) followed by triphosgene (333 mg, 1.12 mmol) solution in dichloromethane (1 mL). The reaction mixture was stirred at room temperature for 1 h. To this mixture was then added 3-(tetrahydrofuran-3-yloxy)aniline (403 mg, 2.25 mmol) in dichloromethane (1 mL). The reaction mixture was stirred at room temperature for 4 h and concentrated. The residue was dissolved in ethyl acetate and washed with water (2×20 mL), brine (10 mL), dried and concentrated. The crude product was purified by flash column chromatography to afford the desired product as a clear oil (221 mg, 0.528 mmol, 47%). 1H NMR: 1.30 (t, 3H, J=7.2 Hz), 2.05-2.15 (m, 2H), 3.68 (s, 2H), 3.81-3.97 (m, 4H), 4.21 (q, 2H, J=7.2 Hz), 4.82 (d, 1H, J=1.6 Hz), 6.49 (dd, 1H, J=8 Hz, 1.6 Hz), 6.71 (d, 1H, J=7.6 Hz), 7.02-7.11 (m, 4H), 7.18 (s, 1H), 7.53 (s, 1H), 7.59 (s, 1H). The reaction mixture was stirred at room temperature for 4 h concentrated The residue was dissolved in ethyl acetate washed with water (2×20 mL), brine (10 mL) dried concentrated The crude product was purified by flash column chromatography

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

Procedure: To a solution of ethyl 2-(4-amino-2-chlorophenyl)acetate (178 mg, 0.833 mmol) in dry dichloromethane (5 mL), was added triethylamine (2.32 mL, 16.66 mmol) followed by triphosgene (247 mg, 0.833 mmol) solution in dichloromethane (1 mL). The reaction mixture was stirred at room temperature for 1 h. To this mixture was then added tert-butyl 2-aminocyclohexylcarbamate (357 mg, 1.67 mmol) in dichloromethane (1 mL). The reaction mixture was stirred at room temperature for 4 h and concentrated. The residue was dissolved in ethyl acetate and washed with water (2×20 mL), brine (10 mL), dried and concentrated. The crude product was purified by flash column chromatography to afford the desired product as a mixture of cis and trans diastereomers (220 mg, 0.485 mmol, 58%). 1H NMR: 1.23-1.28 (m, 6H), 1.38 (s, 9H), 1.70-1.73 (m, 2H), 2.01-2.08 (m, 2H), 3.29-3.32 (m, 1H), 3.53-3.58 (m, 1H), 3.68 (s, 2H), 4.11-4.19 (m, 2H), 5.01 (d, 1H, J=8.8 Hz), 5.57 (d, 1H, J=8 Hz), 7.13 (d, 1H, J=8.4 Hz), 7.20 (d, 1H, J=6.8 Hz), 7.41 (s, 1H), 7.46 (s, 1H). The reaction mixture was stirred at room temperature for 4 h concentrated The residue was dissolved in ethyl acetate washed with water (2×20 mL), brine (10 mL) dried concentrated The crude product was purified by flash column chromatography

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

Procedure: A mixture of 0.600 g of 2-chloro-3-nitro-pyridine (Aldrich) and 0.800 g of (4-amino-2-chloro-phenyl)-acetic acid ethyl ester (see WO 97/21665) in 20 ml of EtOH/dioxane (1:1, v/v) is stirred and refluxed for 72 hours. The mixture obtained is allowed to cool to rt and is concentrated in vacuo. The concentrate obtained is subjected to silica gel column chromatography. A solid is obtained which is triturated with Et2O. [2-Chloro-4-(3-nitro-pyridin-2-ylamino)-phenyl]-acetic acid ethyl ester is obtained in the form of a solid. ES-MS: 336.0 [M+H]+; single peak at tR=5.59 min (System 1); Rf=0.39 (Hexane/EtOAc, 7:3). refluxed for 72 hours The mixture obtained is concentrated in vacuo The concentrate obtained A solid is obtained which is triturated with Et2O