Diels-Alder Rnx: Reaction of cyclopentadiene with maleic anhydride

ephemeral1

Why do we have to redissolve the product we get from the reaction of cyclopentadiene with maleic anhydride? Is it to remove the impurities? The endo-norbornene-5,6-cis-dicarboxylic anhydride product I got from the reaction after the second recrystallization had a melting point 24 degrees lower than the expected melting point. What do you think could affect the final product?

chemisttree

Yes.
An impurity. If you want more specific answers, you need to explain your procedure. In most of these cleanups, hot filtration is used which is notoriously difficult for small samples and first-timers. Easy to get the product a bit crapped up.