反应详情

This is passed through Lober column B (made by Merck) with benzene/acetone (30/1) as an eluent. The product in the earliest fraction is recrystallized from acetone/ether/petroleum ether to give 1.031 g (yield 47%) of the objective ethyl 6-formyl-7,8-dichloro-1,4-benzodioxane-2-carboxylate (Ib'-51), m.p. 101°-102° C. And the product in the later fractions are also recrystallized in the same manner as above to give 1.057 g (yield 49%) of ethyl 5-formyl-7,8-dichloro-1,4-benzodioxane-2-carboxylate (Ib'-50), m.p. 110°-113° C.

1. customThe product in the earliest fraction is recrystallized from acetone/ether/petroleum ether
2. customAnd the product in the later fractions are also recrystallized in the same manner as above