2-Bromopentanenitrile

Conditions: temp:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1.88 g (78.23 mmol) of sodium hydride are added in portions to a solution of 20 g (60.18 mmol) of diallyl 2-(4-methoxycarbonylbenzyl)malonate from Example 12A in 140 ml of DMF at 0° C. The reaction solution is then warmed to 40° C. and is stirred at this temperature for 30 min. The reaction solution is then cooled to 0° C. again and, after addition of 10.73 g (66.20 mmol) of bromovaleronitrile in 140 ml of DMF, stirred at this temperature for 30 min. The mixture is then stirred at room temperature overnight. Water is added dropwise to the reaction mixture and, after extraction three times with ethyl acetate, the combined organic phases are washed with saturated sodium chloride solution and dried over sodium sulfate. After filtration, the solvent is concentrated to dryness in vacuo. The resulting crude product is purified by flash chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate 9:1→4:1). 15.5 g (37.49 mmol, 62% yield) of a colorless solid are obtained. The reaction solution is then cooled to 0° C. again stirred at this temperature for 30 min The mixture is then stirred at room temperature overnight after extraction three times with ethyl acetate the combined organic phases are washed with saturated sodium chloride solution dried over sodium sulfate After filtration the solvent is concentrated to dryness in vacuo The resulting crude product is purified by flash chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate 9:1→4:1)