反应详情

A mixture of 17.45 g of 2-butyl-1,3-propanediol, 26.4 g of diethyl (ethoxymethylidene)-malonate, 250 ml of toluene and 0.285 g of p-toluenesulfonic acid monohydrate was heated to boiling for 1 hour, with moist toluene being distilled off and replaced by the addition of fresh toluene. The reaction mixture was neutralized with triethylamine and, after cooling, washed with saturated sodium chloride solution, dried over sodium sulphate and concentrated. The crude product (42.35 g) was chromatographed on 520 g of silica gel with hexane/ethyl acetate (4:1). 33.0 g of oily diethyl (5-butyl-1,3-dioxan-2-yl)-malonate were obtained.

1. temperaturewas heated
2. distillationdistilled off
3. additionreplaced by the addition of fresh toluene
4. temperatureafter cooling
5. washwashed with saturated sodium chloride solution
6. dry with materialdried over sodium sulphate
7. concentrationconcentrated
8. customThe crude product (42.35 g) was chromatographed on 520 g of silica gel with hexane/ethyl acetate (4:1)