Reaction #6530
ord-8f260ae7aa8349298a8c230f70739320
Reaction equation
Reagents
Solvents
Conditions
Workup
- 1workup.STIRRINGstirring
- 2workup.WAITwas continued overnight
- 3workup.STIRRINGthe mixture was stirred for 48 hours
- 4Concentrationconcentrated
- 5OtherThe residual oil was partitioned between water and ether
- 6Extractionthe aqueous layer was extracted three times with ether
- 7WashThe combined extracts were washed with saturated brine
- 8Dryingdried (MgSO4)
- 9Concentrationconcentrated
- 10OtherThe residue was purified by flash column chromatography
- 11Washeluting with a mixture of petroleum ether (b.p. 60°-80°) and ethyl acetate (1:1
Procedure
Methyl 2-(nicotinoyl)acetate (17.9 g, prepared by the method of E. Wenkert el al. J. Org. Chem., 1983, 48, 5006) was added under argon to a solution of sodium metal (2.3 g) in methanol (200 ml) and the resulting mixture was stirred at 25° C. for 30 mins. Allyl bromide (12.0 g) was then added and stirring was continued overnight. A further amount (about 2 g) of allyl bromide was added, the mixture was stirred for 48 hours, and then concentrated. The residual oil was partitioned between water and ether and the aqueous layer was extracted three times with ether. The combined extracts were washed with saturated brine, dried (MgSO4) and concentrated. The residue was purified by flash column chromatography, eluting with a mixture of petroleum ether (b.p. 60°-80°) and ethyl acetate (1:1, v/v) to give methyl-2-nicotinoyl-4-pentenoate (A) as a pale yellow oil (13.8 g); NMR 2.6-2.9 (2H,m), 3.7 (3H,s), 4.4 (1H,m), 4.9-5.2 (2H,m), 5.5-6.0 (1H,m), 7.2-7.5 (1H,m), 8.1-8.3 (1H,m), 8.7-8.8 (1H,m) and 9.1-9.2 (1H,m).