In this third reaction, we take a look at the conversion to a ketone. The reaction of nitriles with Grignard followed by hydrolysis produces ketones. So we start out first with our nitrile group. Nitrogen is more electronegative, so it's going to be partially negative. Carbon will be partially positive.

If I come in with my Grignard reagent, this bond here would break. The carbon would hit here, kicking one of the pi bonds to nitrogen here. So what we have now is our nitrogen with its two lone pairs and two bonds, so it's negatively charged. We have MgBr positive, and we have this ring attaching itself to this carbon. Now in this form, this is just our intermediate before we do our hydrolysis.

What do we have? We have a CN, we have a carbon double bonded to a nitrogen. Remember that represents an imine functional group. And here we would say that this represents a deprotonated imine. Then we would follow it up with acid hydrolysis or acidic hydrolysis, and that would just remove the nitrogen entirely and leave behind an oxygen, forming our ketone as the final product.

So again, a great way of transforming a nitrile into a ketone is through the introduction of a Grignard reagent followed by hydrolysis.