residue is treated with ice. The aqueous suspension is extracted with benzene (about 300 ml), and the organic phase is at once chromatographed on acid A1203. Benzene (1000 ml) is used for elution. After evaporation of the solvent the residue is taken up in ether, and the solution is decanted at once into a suspension of NaNHz prepared from sodium (6 g) and iron(1Ir) nitrate (0.3 g) in liquid ammonia (400 ml) at -40 "C. The mixture is stirred for 2 h at -40 'C. Ammonium chloride (15 g) is added to decompose the excess of sodium amide, and the ammonia is allowed to evaporate overnight. The mixture is then hydrolyzed with dilute sulfuric acid, and the organic component is extracted into ether. After evaporation of the ether the residue is chromatographed in benzene on acid A1203. The eluate is evaporated and the residue is kept at -30Β°C for 2 days. Yield: 1.2 g (CLI. 25 %) of colorless leaflets, m.p. 49 "C.
Reactions of Cyclopentodienone Derivutives with 2,2'-Diethynylbiphenyl 1 mole of (3) and 2 moles of the cyclopentadienone derivative are heated in a small volume of 2-decal01 under nitrogen until gas evolution ceases and decoloration is almost complete (several hours). After cooling, the product is filtered off and recrystallized from ethyl acetate or o-dichlorobenzene.