反应详情

To a solution of triethyl phosphonoacetate (15.0 g) in tetrahydrofuran (60 ml) cooled in an ice bath was added butyllithium (2.5M in hexanes, 25.6 ml) at a rate such that the internal temperature was maintained below 30° C. To this mixture was then added a solution of the product of Example 2 step (b) (10.0 g) in N,N-dimethylformamide (60 ml). The reaction mixture was heated at reflux for 1 hour, then cooled to room temperature and quenched with acetic acid (6 ml). The solid thus precipitated was isolated by filtration, washed with water, ethanol and diethyl ether, and dried over P2O5 at 50° C. to give the sub-titled product as a pale green solid (9.3 g).

1. temperaturewas maintained below 30° C
2. temperatureThe reaction mixture was heated
3. temperatureat reflux for 1 hour
4. customquenched with acetic acid (6 ml)
5. customThe solid thus precipitated
6. customwas isolated by filtration
7. washwashed with water, ethanol and diethyl ether
8. dry with materialdried over P2O5 at 50° C.