Are highly nitrated cyclopentadiene compounds possible?

Has anybody synthesized di- or higher nitrated cyclopentadienes possibly with methyl or other groups in the 1 position (analogs of TNT)?




Mono-nitrated cyclopentadienes and their benzo-analogues (indene, fluorene) have been prepared in the context of studies on *nitro-aci*-tautomerism.


As far as higher substitution is concerned, there seems to be at least a crystal structure of [potassium dinitrotrichlorocyclopentadienide](http://dx.doi.org/10.1107/S0567740872004637) reported in *Acta Cryst., B*


In the abstract, the authors (Y. Otaka, F. Marumo, and Y. Saito) mention the preparation of this compound by **Haga** in 1969, (sorry, reference is behind paywall) via 



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> nitration of hexachlorocyclopentadiene with alkali nitrite in an aqueous or ethanolic solution
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> 


NOTE: Hexachlorocyclopentadiene once was a favoured starting material in the synthesis of insecticides via Diels-Alder reaction. However, it is a **potent teratogen** and the "mother" of least five members of the **dirty dozen** (persistent organic pollutants) nowadays banned for good reason.


You might want to read the MSDS and then decide that you'd rather prefer to work with something else.


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