反应详情

温度

-50 °C

The procedure is as according to the method described for preparation III, but maintaining the temperature at -50° C. From 186 g (7.7×10-1M) of bromo-methoxy-chroman Ib2 in 500 cm3 of anhydrous ether and 7.7×10-1M of n-butyllithium in 650 cm3 of anhydrous ether, and after addition of 78 g (1.1 M) of N,N-dimethylformamide in 200 cm3 of anhydrous ether and recrystallisation in isopropyl ether, 75 g (yield=51%) of expected compound are isolated. m.p.=81° C.