Question

Hydrazine reacts with 2,4-pentanedione to yield 3,5-dimethylpyrazole. Including protonations and deprotonations, the reaction takes 12 steps. Write out the mechanism on a sheet of paper and then draw the structure of the product of step 9.

Answer 1

Step-by-step explanation:

From the given information:

We explained the reaction mechanism of 2,4-pentanedione with hydrazine to yield 3,5-dimethylpyrazole as shown below;

At the initial stage, the carbonyl oxygen gains a proton, increasing the carbonyl carbon's electrophilicity. After that, the carbonyl carbon is being attacked by hydrazine. Then, the process proceeds with the species formed where removal of a proton takes place. Similarly, hydroxyl oxygen gains a proton. After that, the water molecule is being removed, and further rearrangement of an electron occurs at the site of nitrogen in hydrazine.

From species formed, the removal of a proton takes place. Finally, all step is being repeated to yield the final product known as 3,5 - dimethylpyrazole.