2-N-ethylbenzene-1,2-diamine

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

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

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

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

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

Procedure: N-Ethyl-2-nitroaniline (0.97 g, 5.8 mmol) was dissolved in EtOAc (60 mL) and placed in a closed vessel. 10% Pd/C (0.4 g, 7 mol %) was added and the mixture was hydrogenated under 50 psi H2 for 2 h. The mixture was filtered through celite and the filtrate was concentrated under reduced pressure to yield the title product (0.79 g, 99%) as a brown liquid, which was used without further purification. 1H-NMR (CDCl3): δ 6.83 (1H, m), 6.64-6.74 (3H, m), 3.29 (3H, br s), 3.15 (2H, q), 1.30 (3H, t); TLC (2:98 MeOH/DCM Rf 0.24). placed in a closed vessel The mixture was filtered through celite the filtrate was concentrated under reduced pressure

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

Procedure: To a solution of crude N-ethyl-benzene-1,2-diamine (8.4 g, 62 mmol) in anhydrous tetrahydrofuran (200 mL) was added 1,1′-carbonyldiimidazole (10 g, 62 mmol). The mixture was stirred at room temperature under nitrogen for 12 hours and ethyl acetate (250 mL) followed by a cold 3N aqueous solution of hydrochloric acid (200 mL) were added. The organic layer was separated, dried over sodium sulfate and concentrated in vacuo to afford 1-ethyl-1,3-dihydro-benzimidazol-2-one as a white solid (8.5 g, 69% for three steps). MS (ES) m/z 163.2. were added The organic layer was separated dried over sodium sulfate concentrated in vacuo

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

Procedure: To a solution of ethyl-(2-nitro-phenyl)-amine (12.5 g, 75 mmol) in anhydrous tetrahydrofuran (150 mL) was added sodium borohydride (5.8 g, 153 mmol), and 5% palladium on carbon (150 mg). Methanol (25 mL) was then added at room temperature under nitrogen in a dropwise manner. After addition, the reaction mixture was stirred at room temperature for about 30 minutes until the reaction was complete. The reaction mixture was then filtered through a pad of Celite. The filtrate was diluted with ethyl acetate (200 mL), washed with a saturated aqueous solution of ammonium chloride (80 mL), dried over sodium sulfite, and concentrated in vacuo to afford crude N-ethyl-benzene-1,2-diamine (8.4 g, 62 mmol) which was used in next step without further purification. After addition The reaction mixture was then filtered through a pad of Celite The filtrate was diluted with ethyl acetate (200 mL) washed with a saturated aqueous solution of ammonium chloride (80 mL) dried over sodium sulfite concentrated in vacuo

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

Procedure: 5,4 g (39,6 mM) of N-ethylbenzene-1,2-diamine and 2,76 ml (39,6 mM) of 2-oxopropanoic acid in 200 ml of methanol were refluxed for 8 h. The solvent was removed under vacuum. The residue was further purified by silica gel column chromatography, using dichloromethane, followed by dichloromethane/dimethylketone (95/5) as eluant to give 4,2 g of 1-ethyl-3-methyl-quinoxalin-2(1H)-one as a yellow solid. Yield: 56,7%. The solvent was removed under vacuum The residue was further purified by silica gel column chromatography

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To 12 g (88.1 mmol) of N-ethylbenzene-1,2-diamine in 150 ml of methanol were added dropwise 8.1 g (92.5 mM) of oxalyl chloride. The exothermic mixture reached 55° C. and solidified. The mixture was heated at 130° C. for 2 h. The purple solid formed was filtered and washed with isopropanol to give 1-ethyl-1,4-dihydroquinoxaline-2,3-dione as a solid (7.2 g). Yield: 43%. reached 55° C. The purple solid formed was filtered washed with isopropanol

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

Procedure: 5.4 g (39.6 mM) of N-ethylbenzene-1,2-diamine and 2.76 ml (39.6 mM) of 2-oxopropanoic acid in 200 ml of methanol were refluxed for 8 h. The solvent was removed under vacuum. The residue was further purified by silica gel column chromatography, using dichloromethane, followed by dichloromethane/dimethylketone (95/5) as eluant to give 4.2 g of 1-ethyl-3-methyl-quinoxalin-2(1H)-one as a yellow solid. Yield: 56.7%. The solvent was removed under vacuum The residue was further purified by silica gel column chromatography

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To 12 g (88.1 mmol) of N-ethylbenzene-1,2-diamine in 150 ml of methanol were added dropwise 8.1 g (92.5 mM) of oxalyl chloride. The exothermic mixture reached 55° C. and solidified. The mixture was heated at 130° C. for 2 h. The purple solid formed was filtered and washed with isopropanol to give 1-ethyl-1,4-dihydroquinoxaline-2,3-dione as a solid (7.2 g). Yield: 43%. reached 55° C. The purple solid formed was filtered washed with isopropanol

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

Procedure: N-Ethyl-2-nitroaniline (0.97 g, 5.8 mmol) was dissolved in EtOAc (60 mL) and placed in a closed vessel. 10% Pd/C (0.4 g, 7 mol %) was added and the mixture was hydrogenated under 50 psi H2 for 2 h. The mixture was filtered through celite and the filtrate was concentrated under reduced pressure to yield the title product (0.79 g, 99%) as a brown liquid, which was used without further purification. 1H-NMR (CDCl3): δ 6.83 (1H, m), 6.64–6.74 (3H, m), 3.29 (3H, br s), 3.15 (2H, q), 1.30 (3H, t); TLC (2:98 MeOH/DCM Rf 0.24). placed in a closed vessel The mixture was filtered through celite the filtrate was concentrated under reduced pressure