Allyl Alcohol

[37 p459, 146 p42]--This chemical is not only useful in Frie-del-Crafts reactions but is the major stepping stone for making al-lyl bromide which has wide uses. The set up to use is a simple distillation apparatus (no vacuum,bubba!) with a tube leading away from the vacuum adapter to a NaOH solution trap. 400g glycerol and 175g 88% formic acid are placed in the reaction flask and rapidly heated so that it reaches 195°C in about 30-45 minutes during which time C02 and a little distillate will evolve. At this time the receiving flask is exchanged with a clean one and heating is continued until a second wave of distillation occurs between the temperatures 225-260°C. After 260°C is reached the reaction flask is allowed to cool to about 115°C, 125g more formic acid is added and the solution heated again to 260°C collecting all the distillate that comes over between 195-260°C into the same receiving flask. A third formic acid addition is done to insure that as much allyl alcohol as possible is obtained. What the chemist has collected is neutralized with a little potassium carbonate and the allyl alcohol is distilled collecting the fraction comes over below 99°C. What the chemist is going to have now is about 21 Og of an aqueous solution that is 70% allyl alcohol. This can be made anhydrous by refluxing it with potassium carbonate, distilling and collecting the fraction that comes over between 94-97°C. What the chemist should really do is use the 70% solution directly in the production of the more preferable allyl bromide in the next recipe.

Continue reading here: Allyl Bromide

Was this article helpful?

0 0