反应详情

To a solution of 2,2,6,6-tetramethylpiperidine (5.1 ml, 30.4 mmole) in dry tetrahydrofuran (60 ml), cooled at -78° C. (dryice/acetone) under an argon atmosphere, was added dropwise n-butyllithium (17.3 ml, 27.6 mmole). After the addition the reaction was warmed to -10° C. (ice/acetone). To this solution was added N,N-diethyl-2-methylfuran-3-carboxamide (5.0 g, 27.6 mmole) in tetrahydrofuran (15 ml). After stirring this mixture for 1.0 hour, 3-(dimethylamino)propionitrile (3.27 ml, 29.0 mmole) was added dropwise. The reaction was allowed to warm overnight. The reaction was poured into ice/water and acidified to a pH 3.25 with hydrochloric acid. The mixture was then extracted with diethyl ether (3×150 ml). The pH of the aqueous layer was adjusted to 13.0 using sodium hydroxide solution (40%) and this solution was extracted exhaustively using methylene chloride (10×150 ml). The combined extracts were washed with water (2×50 ml), brine (2×100 ml) and dried (MgSO4). After solvent evaporation 8.25 g of an oil was obtained. This was purified by flash chromatography using 15% methanol/chloroform as the eluting solvent to give analytically pure product (4.65 g, 82% yield), mp: 97.5°-98.0° C. Some starting amide (1.05 g) was recovered from the initial diethyl ether extracts.

1. additionAfter the addition the reaction
2. temperatureto warm overnight
3. extractionThe mixture was then extracted with diethyl ether (3×150 ml)
4. extractionthis solution was extracted exhaustively using methylene chloride (10×150 ml)
5. washThe combined extracts were washed with water (2×50 ml), brine (2×100 ml)
6. dry with materialdried (MgSO4)
7. customAfter solvent evaporation 8.25 g of an oil
8. customwas obtained
9. customThis was purified by flash chromatography