反应详情

A solution of the 2-methoxy-4,5-methylenedioxy benzaldehyde (16.0 g, 0.089 mol), diethyl malonate (15.0 ml, 0.090 mol), piperidine (4.4 ml, 0.044 mol) and acetic acid (2.5 ml, 0.045 mol) in benzene (75 ml) stirred at reflux, equipped with a Dean-Stark apparatus, for 24 h. Upon removal of the solvent the crude residue was extracted with ethyl acetate and washed with 10% sodium carbonate solution, water, dried (Na2SO4). After removing the solvent, flash chromatography of the residue (silica gel, 25% ethyl acetate/hexane) provided the title compound as a yellow solid (26.0 g, 91%).

1. temperatureat reflux
2. customequipped with a Dean-Stark apparatus, for 24 h
3. customUpon removal of the solvent the crude residue
4. extractionwas extracted with ethyl acetate
5. washwashed with 10% sodium carbonate solution, water
6. dry with materialdried (Na2SO4)
7. customAfter removing the solvent, flash chromatography of the residue (silica gel, 25% ethyl acetate/hexane)