反应详情

温度

-70 °C

A solution of 15.8 g of 3-bromopyridine (0.10 mol) in 50 ml of diethyl ether is added dropwise to a mixture of 82 ml of a 1.6M n-butyllithium solution in n-hexane (0.13 mol) under a nitrogen atmosphere at -70° C. The mixture is stirred at -70° C. for 10 minutes and then a solution of 24.7 g of 2-(4-chlorobenzyl)-2-ethylbutanal (0.11 mol) in 50 ml of diethyl ether is added dropwise. After 1 h at -70° C., the mixture is allowed to warm slowly to room temperature and is hydrolyzed with saturated aqueous ammonium chloride solution. The mixture is acidified with dilute hydrochloric acid, and the aqueous phase is separated off and washed with ether and then adjusted to pH 10 to 11 with concentrated ammonia solution while cooling. It is extracted three times with dichloromethane, and the organic phase is dried over Na2SO4 and concentrated. The solid crude product is recrystallized from ethyl acetate/hexane (1:1). 19.2 g (63% of theory) of colorless crystals of melting point 128°-129° C.

1. waitAfter 1 h at -70° C.
2. temperatureto warm slowly to room temperature
3. customthe aqueous phase is separated off
4. washwashed with ether
5. temperaturewhile cooling
6. extractionIt is extracted three times with dichloromethane
7. dry with materialthe organic phase is dried over Na2SO4
8. concentrationconcentrated
9. customThe solid crude product is recrystallized from ethyl acetate/hexane (1:1)