Reaction of N-Methyl-hydrazones as Azaenamines with Quinones

1,4-Naphthoquinone derivatives reacted with N,N-disubstituted hydrazones to give C adducts, whereas N-monoalkylhydrazones yielded N adducts which underwent ring closure to benzindazole-4,9-diones. Michael addition with methoxycarbonylbenzoquinone led to open chain mono- and disubstituted N adducts or phthalazin-1-one derivatives, depending on the hydrazone. N Adducts obtained from dimethylbenzoquinone cyclized by hetero Diels–Alder reaction to benzoxadiazines.