反应详情

NaH (0.38 g, 9.5 mmol, 60% paraffin oil) was added slowly to a THF (20 mL) solution of ethyl (tetrahydro-2H-pyran-2-yloxy)acetate (prepared by treating ethyl hydroxyacetate with 3,4-dihydro-2H-pyran and TsOH) (1.0 g, 5.3 mmol) and dry ethyl formate (3.9 g, 53 mmol). The reaction mixture was stirred at room temperature for 15 min. and then heated at 65° C. for 45 min. The reaction mixture was concentrated to dryness to give a pale yellow solid. The solid was added to a MeOH/EtOH (20 mL/20 mL) solution of (2E)-3-phenyl-2-propenimidamide (0.78 g, 5.3 mmol), the subsequent mixture was heated at 80° C. for 4 h. The resulting material was poured into DCM (10 mL) containing silica gel (3 g) and evaporated. Purification by column chromatography (silica gel) using a MeOH/DCM gradient (0-10%) provided the desired product as a pale yellow solid (1 g, 63%).

1. temperatureheated at 65° C. for 45 min
2. concentrationThe reaction mixture was concentrated to dryness
3. customto give a pale yellow solid
4. temperaturethe subsequent mixture was heated at 80° C. for 4 h
5. additioncontaining silica gel (3 g)
6. customevaporated
7. customPurification by column chromatography (silica gel)