反应详情

4.13 ml of 1.6M n-butyl lithium in hexane are added dropwise to a tetrahydrfuran solution of 0.76 g of 1-ethoxymethylpyrazole at -60° C. under argon gas atmosphere. the mixture is stirred at -63° to -50° C. for 1 hour. A solution of 1.23 g of 2,3-dichloro-4-methoxybenzaldehyde in tetrahydrofuran is added to the mixture, and the mixture is stirred at -50° C. to room temperature for 1 hour. An aqueous saturated ammonium chloride solution and water are added to the mixture under ice-cooling and the mixture is concentrated to remove tetrahydrofuran. The residual aqueous layer is extracted with ethyl acetate and the extract is washed with water, dried and evaporated to give colorless crystals, which are then washed with isopropyl ether and dried to give 1.62 g of α-(1-ethoxymethyl-5-pyrazolyl)-2,3-dichloro-4-methoxy-benzylalcohol.

1. stirringthe mixture is stirred at -50° C. to room temperature for 1 hour
2. temperaturecooling
3. concentrationthe mixture is concentrated
4. customto remove tetrahydrofuran
5. extractionThe residual aqueous layer is extracted with ethyl acetate
6. washthe extract is washed with water
7. customdried
8. customevaporated
9. customto give colorless crystals, which
10. washare then washed with isopropyl ether
11. customdried