5-chloro-3,4-dihydro-1H-quinoxalin-2-one

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

Procedure: Following the same procedure as described for Example 1C, 5-chloro-3,4-dihydro-1H-quinoxalin-2-one from Example 12D (350 mg, 1.9 mmol) was reacted with sodium hydride (60%, 84 mg, 2.1 mmol) and tert-butyl bromoacetate (340 μl, 2.1 mmol). The product was purified by flash chromatography on silica (eluant pet. ether:EtOAc 100:0 to 50:50) to give a brown solid; yield 450 mg, 79%. The product was purified by flash chromatography on silica (eluant pet. ether:EtOAc 100:0 to 50:50) to give a brown solid

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

Procedure: Following the same procedure as described for Example 1C, 5-chloro-3,4-dihydro-1H-quinoxalin-2-one from Example 12D (350 mg, 1.9 mmol) was reacted with sodium hydride (60%, 84 mg, 2.1 mmol) and tert-butyl bromoacetate (340 μl, 2.1 mmol). The product was purified by flash chromatography on silica (eluant pet. ether:EtOAc 100:0 to 50:50) to give a brown solid; yield 450 mg, 79%. The product was purified by flash chromatography on silica (eluant pet. ether:EtOAc 100:0 to 50:50) to give a brown solid

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

Procedure: 4-tert-Butyl-5-chloro-3,4-dihydro-1H-quinoxalin-2-one from Example 12C (1.5 g, 6.1 mmol) was suspended in 2N sulphuric acid (45 ml) and stirred for 18 h. The mixture was filtered and the filtrate was neutralised with sodium hydrogen carbonate, extracted with EtOAc, dried and evaporated. The residue was taken up in ethanol (30 ml) and cooled in an ice/water bath. Sodium borohydride (460 mg, 12 mmol) was added and the mixture was allowed to warm to room temperature over 2 h. Water (1 ml) was added and the mixture was evaporated. The residue was triturated with ice-cold water, filtered, washed with ice-cold water and dried in vacuo over phosphorous pentoxide to give an orange solid; yield 550 mg, 49%. The mixture was filtered extracted with EtOAc dried evaporated cooled in an ice/water bath the mixture was evaporated The residue was triturated with ice-cold water filtered washed with ice-cold water dried in vacuo over phosphorous pentoxide to give an orange solid

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

Procedure: Following the same procedure as described for Example 1C, 5-chloro-3,4-dihydro-1H-quinoxalin-2-one from Example 12D (350 mg, 1.9 mmol) was reacted with sodium hydride (60%, 84 mg, 2.1 mmol) and tert-butyl bromoacetate (340 μl, 2.1 mmol). The product was purified by flash chromatography on silica (eluant pet. ether:EtOAc 100:0 to 50:50) to give a brown solid; yield 450 mg, 79%. The product was purified by flash chromatography on silica (eluant pet. ether:EtOAc 100:0 to 50:50) to give a brown solid

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

Procedure: 4-tert-Butyl-5-chloro-3,4-dihydro-1H-quinoxalin-2-one from Example 12C (1.5 g, 6.1 mmol) was suspended in 2N sulphuric acid (45 ml) and stirred for 18 h. The mixture was filtered and the filtrate was neutralised with sodium hydrogen carbonate, extracted with EtOAc, dried and evaporated. The residue was taken up in ethanol (30 ml) and cooled in an ice/water bath. Sodium borohydride (460 mg, 12 mmol) was added and the mixture was allowed to warm to room temperature over 2 h. Water (1 ml) was added and the mixture was evaporated. The residue was triturated with ice-cold water, filtered, washed with ice-cold water and dried in vacuo over phosphorous pentoxide to give an orange solid; yield 550 mg, 49%. The mixture was filtered extracted with EtOAc dried evaporated cooled in an ice/water bath the mixture was evaporated The residue was triturated with ice-cold water filtered washed with ice-cold water dried in vacuo over phosphorous pentoxide to give an orange solid