Tropone hydrazone

The reaction of tropone hydrazone with phenylsulfene in the presence of triethylamine gave a [8 + 2] cycloadduct (equation 132) in 48% yield217. 

In the reaction of the tropothione -sulfide 34, obtained from tropone hydrazone and disulfur dichloride, at -78 °C in the presence of dimethyl acetylenedicarboxylate, the [IOtt + 7t] cycloadduct 35 was obtained in 23 % yield... 

Other imino derivatives arise, as by-products or in side reactions, on heterocyclization. Thus, the treatment of cinnamoyltropolones 75 with hy-droxylamine (Scheme 19) yields, in the case of the 5-nitro derivative, the corresponding isoxazolotroponeoxime (89JHC371). The formation of oximes and several hydrazones from 3-acetyltropolone or its derivatives has also been mentioned (Section II,A,3,c). Moreover, an azine was obtained in addition to quinoxalotropone 213 (Section II,B,2,c) a tropone immonium salt was isolated after an extremely complex diene reaction of an 6-amino-2-azaazuIene (93CB441). 

Hydrazones. The reagent is prepared from A(,Af-dimethylhydrazine and trimethylaluminum in hot toluene (97% yield). It is useful for derivatization of unre-active ketones (e.g., ferrocenyl ketones) in refluxing toluene. The fully substituted hydrazones can undergo exchange on reaction with N2H4 in ethanol. Tropone hydra-zone, which has previously been unavailable, can be prepared by this method. 

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