Hydrazones dimethyl, elimination reactions

Treatment of a mixture of acetophenone phenylhydrazone and dimethyl acetylenedi-carboxylate with aluminium chloride gives the ene hydrazone 98, which undergoes a spontaneous Fischer indole reaction to yield the pyrrole 99 with elimination of aniline (equation 41)62. 

MyV-Dimethylhydrazones of aldehydes react with hydrogen peroxide in the presence of catalytic amounts of MTO to give the corresponding nitriles in high yield [19]. The reaction commences with the oxidation of the Af,A -dimethyl-hydrazone and presumably proceeds through an intermediate which can undergo a Cope-type elimination to yield the nitrile (eq. (8)) [3, 19 b]. 

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