反应详情

In a mixed solvent of 20 ml of ethanol and 8 ml of pyridine was dissolved 3.9 g of 5-acetoxy-4,6-di-t-butyl-2-formyl-2-methyl-2,3-dihydrobenzofuran, and 1.42 g of aminoguanidine hydrochloride was added at room temperature. After heating under reflux for 14 hours and then cooling, ethanol and excess pyridine were distilled off using an evaporator, and the concentrate was combined with water and extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and then concentrated. The concentrate was purified by silica gel column chromatography eluting with chloroform containing 10% methanol to give 4.48 g of 1-[(5-acetoxy-4,6-di-t-butyl-2-methyl-2,3-dihydrobenzofuran-2-yl)methylideneamino]guanidine (rotamer mixture) as a pale yellow oil (yield 99%).

1. additionwas added at room temperature
2. temperatureAfter heating
3. temperatureunder reflux for 14 hours
4. temperaturecooling
5. distillationethanol and excess pyridine were distilled off
6. customan evaporator
7. extractionextracted with ethyl acetate
8. washThe organic layer was washed with saturated brine
9. dry with materialdried over anhydrous magnesium sulfate
10. concentrationconcentrated
11. customThe concentrate was purified by silica gel column chromatography
12. washeluting with chloroform containing 10% methanol