Why did magnesium not react in grignard reaction?
In our chem lab class, we had to produce 5-methyl-5-nonanol via a grignard reaction using magnesium, 1-bromobutane, ethyl acetate, and sulfuric acid. We acetone dried all our glassware and made sure to the best of our ability that no moisture was present, but throughout the reaction, the magnesium did not dissolve from the reaction flask. Understandably, this messed up the entire experiment. I am having trouble figuring out why this would happen...please help?
- GeorgeLv 47 years agoFavorite Answer
I normally sand down the magnesium before putting it into the reaction. If the magnesium is exposed to air, a layer of magnesium oxide forms on the surface and makes the metal unreactive.
Furthermore, once in the reaction, you can (very gently) grind the magnesium with a glass rod. If an oxide layer is present, this will hopefully remove it.