# What is the reaction between diethyl malonate and hydrazine?

For the reaction of diethyl malonate with $$\ce{NH2NH2}$$ in aqueous medium in presence of $$\ce{CH3CH2OH}$$, I found two types of product with SciFinder:

In presence of $$\ce{H2SO4}$$, the reaction changes to:

$$\ce{EtOH}$$ is a good leaving group, but can you explain why there are two different types of products? With what mechanism can they be explained?

• The second reaction looks similar to the Nazarov cyclization. The sulfuric acid must dehydrate and provide the protic properties required for the ring formation. – Technetium Nov 26 '15 at 3:26
• Can you please explain in detail about Nazarov cyclization? – Mitradip Das Nov 26 '15 at 3:27
• I can't provide a proper answer in the acceptable format for this site on my cheap phone sorry but type it in to Google there's plenty of credible information about it (: – Technetium Nov 26 '15 at 3:31
• Try @ Nazarov cyclization reaction Wikipedia. – Technetium Nov 26 '15 at 3:34