Benzenediazonium carboxylate decomposes when heated to yield N2, C02, and a reactive substance that can't be isolated.

Question:

Benzenediazonium carboxylate decomposes when heated to yield N2, C02, and a reactive substance that can't be isolated. When Benzenediazonium carboxylate is heated in the presence of furan, the following reaction is observed: What intermediate is involved in this reaction? Propose a mechanism for itsformation.