Imidazole → 1-(Pent-2-enyl)imidazole

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.

1. temperaturerefluxing
2. additionAfter addition
3. temperatureunder reflux for a further 24 hours
4. filtrationThe mixture was filtered
5. customto remove unsoluble material
6. customthe filtrate evaporated
7. customto remove solvent
8. washwashed with ether (50 ml)
9. extractionextracted with chloroform (3×50 ml)
10. dry with materialCombined extracts dried over anhydrous MgSO4 and chloroform
11. customremoved under vacuum
12. customto leave crude product which
13. customwas purified on silica gel column (EtOAc/MeOH 9:1 was used as eluent)
14. customProduct fractions were collected
15. distillation1.0 g was distilled under vacuum

ORD record

ord-f159a88e983e422e906ceecdd9ed029e

Source dataset

uspto-grants-1981_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04284641