反应详情

To a stirred solution of hex-2-enoic acid ethyl ester (A) (450 g, 3.164 mol, 1 eq) in nitromethane (858 ml, 15.822 mol, 5 eq) cooled at 0° C., is added dropwise, under nitrogen, 481.8 g (3.164 mol, 1 eq.) of 1.8-diazabicyclo[5.4.0]undec-7-ene (DBU). The reaction mixture is allowed to react at room temperature for 3 h and is quenched with a 6M aqueous hydrogen chloride solution to obtain pH=4. The solution is extracted with diethyl ether (500 ml+2×300 ml). The organic layers are dried with MgSO4, filtered and concentrated to obtain an oil residue (672.13 g, HPLC purity=78.9%) which is purified by liquid chromatography eluting with dichloromethane. 639.41 g of 3-nitromethyl-hexanoic acid ethyl ester (B) are obtained (yield=99.4%).

1. additionis added dropwise, under nitrogen
2. customto react at room temperature for 3 h
3. customis quenched with a 6M aqueous hydrogen chloride solution
4. customto obtain pH=4
5. extractionThe solution is extracted with diethyl ether (500 ml+2×300 ml)
6. dry with materialThe organic layers are dried with MgSO4
7. filtrationfiltered
8. concentrationconcentrated
9. customto obtain an oil residue (672.13 g, HPLC purity=78.9%) which
10. customis purified by liquid chromatography
11. washeluting with dichloromethane