(3,5,5-Trimethyl-2-cyclohexen-1-ylidene)propanedinitrile 23051-44-7 3-Dicyanomethylene-1,5,5-trimethylcyclohexene C-1668 Propanedinitrile, (3,5,5-trimethyl-2-cyclohexen-1-ylidene)-