Butyl bromide → n-Butyl cyclopentadiene

Participants

Reaction Conditions

Reaction Steps

To 1-bromobutane (105 g, 0.766 mol) was added cyclopentadienyl magnesium chloride (800 mL of 1 M solution in THF, 0.8 mol) at 0° C. in 20 minutes. After stirring for an additional 2 hours at 0° C., the mixture was warmed to room temperature. After stirring overnight, the reaction was quenched with a mixture of ice and water. The mixture was extracted with pentane. The organic layer was washed with water and dried over anhydrous sodium sulfate. Removal of the solvent under vacuum at room temperature gave a brown liquid (85 g, crude butylcyclopentadiene). To the crude butylcyclopentadiene (75 g) dissolved in methanol (500 mL) was added acetone (54 mL) followed by pyrrolidine (63 mL) at 0° C. The mixture was warmed up to room temperature and stirred for 24 hours. The reaction was quenched with a mixture of ice and acetic acid. The mixture was extracted with pentane. The organic layer was washed with water and dried over anhydrous sodium sulfate. Removal of the solvent under vacuum gave the desired product (89 g) as a brown liquid.

Provenance & Evidence