1,2,4-Ethanylylidene-1H-cyclobuta(cd)pentalen-3-amine, octahydro-N-ethyl-, hydrochloride 136375-80-9 8-(Ethylamino)pentacyclo(5.4.0.0(sup 2,6).0(sup 3,10).0(sup 5,9))undecane hydrochloride