Dabco → Ethyl 5-cyclopropylisoxazole-3-carboxylate

Reaction equation

[C:1]([CH:3]1[CH2:5][CH2:4]1)#[CH:2].[N+:6]([CH2:9][C:10]([O:12][CH2:13][CH3:14])=[O:11])([O-])=[O:7].C1N2CCN(CC2)C1>C(O)C>[CH:3]1([C:1]2[O:7][N:6]=[C:9]([C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH:2]=2)[CH2:5][CH2:4]1

Participants

Procedure

A solution of ethynylcyclopropane (0.40 mL; 4.58 mmol), ethyl 2-nitroacetate (1.30 mL; 11.46 mmol), and 1,4-diazobicyclo[2.2.2]octane (DABCO, 0.053 g; 0.458 mmol) in ethanol (3 mL) was irradiated in a microwave oven at 150° C. for 20 min and was then evaporated. The residue was dissolved in ethyl acetate and the solution was washed with water. The organic layer was evaporated and the residue was purified by flash chromatography on silica gel (eluent: 20 to 100% of dichloromethane in heptane) to afford 0.765 g (92%) of ethyl 5-cyclopropylisoxazole-3-carboxylate as a yellow oil.