反应详情

A solution of 3-bromo-5-methoxybenzaldehyde (3.93 g, 18.2 mmol), propane-1,3-diol (1.6 mL, 21.8 mmol) and p-toluenesulfonic acid monohydrate (0.104 g, 0.54 mmol) in anhydrous toluene (100 mL) was brought to reflux for 18 h under nitrogen. During this time water was removed using a Dean-Stark apparatus. After this time the reaction was cooled to rt, washed with 5% aqueous Na2CO3 solution (50 mL) and dried over anhydrous Na2SO4. The reaction was concentrated under reduced pressure to give 2-(3-bromo-5-methoxyphenyl)-1,3-dioxane (4.80 g, 96%) as a brown oil.

1. temperatureto reflux for 18 h under nitrogen
2. customDuring this time water was removed
3. washwashed with 5% aqueous Na2CO3 solution (50 mL)
4. dry with materialdried over anhydrous Na2SO4
5. concentrationThe reaction was concentrated under reduced pressure