Imidazole → 1-(Pent-2-enyl)imidazole

Participants

Reaction Steps

Pent-2-enyl bromide (18.5 g) was added dropwise to a stirred refluxing mixture of imidazole (10 g) and sodium bicarbonate (12.4 g) in methanol (50 ml). After addition was complete, the mixture was stirred under reflux for a further 24 hours. The mixture was filtered to remove unsoluble material and the filtrate evaporated to remove solvent. Residue taken in 2N-HCl (150 ml) and washed with ether (50 ml). The aqueous layer was basified with 10N NaOH and extracted with chloroform (3×50 ml). Combined extracts dried over anhydrous MgSO4 and chloroform removed under vacuum to leave crude product which was purified on silica gel column (EtOAc/MeOH 9:1 was used as eluent). Product fractions were collected; total weight 4.9 g. 1.0 g was distilled under vacuum; yield 1.08 g. B.p. 134° C./15 mmHg. Micro analysis: C8H12N2 requires C,70.59; H,8.82; N,20.59. Found: C,69.72, H,8.88; N,20.43.

Provenance & Evidence