反应详情

To an ice cold solution of ethylcyanoacetate (10.9 mL, 102.4 mmol) in anhydrous THF (170 mL) under nitrogen, was added potassium tert-butoxide (12.7 g, 107.5 mmol). The formed white suspension was stirred for 15 minutes, then treated with 2,3-dichloronitrobenzene (9.83 g, 51.2 mmol). The suspension was heated at reflux for 48 hours. The resulting reddish brown solution was poured into water, and the aqueous mixture was acidified to pH 2 with concentrated HCl. The mixture was extracted with ether (3×150 mL) and then the combined organic phase was dried (using Na2SO4) and concentrated to give a dark oil. Flash chromatography using 10:1 hexane:ethyl acetate in a column packed with silica gel, 10 times the weight of the dark oil, provided a viscous yellow liquid 4, which was used without further purification for the next step. TLC Rf 0.23 (hexane-ethyl acetate 3:1). 1H NMR δ 1.33-1.38 (t, 3H, CH3); 4.29-4.35 (q, 2H, CH2); 7.59-8.14 (m, 3H, phenyl).

1. temperatureThe suspension was heated
2. temperatureat reflux for 48 hours
3. extractionThe mixture was extracted with ether (3×150 mL)
4. dry with materialthe combined organic phase was dried (using Na2SO4)
5. concentrationconcentrated
6. customto give a dark oil