The nitration method of aromatic compounds using a mixture of metal nitrates and acetic anhydride, commonly called the Menke method, was applied for the synthesis of 5- and 3-nitroacenaphthenes. 5-Nitroacenaphthene was obtained in a yield of ca. 90% even at 30°C, when an amount of metal nitrate equivalent to the acenaphthene dissolved in acetic anhydride was added. However, 3-nitroacenaphthene was formed together with the 5-isomer by the reversed treatment at -10°C in a yield of 18%. Of various metal nitrates tested, cupric and zinc nitrates proved most satisfactory.
Carboxylation reactions of sodium phenoxide under carbon dioxide pressure in a liquid state were studied. The effects of the physical and chemical properties of solvents on the yield of hydroxy carboxylic acids and the ratio of p-isomer/o-isomer were clarified. On the whole, the yield of the desired product attained by this treatment was poorer than that by the gas-solid state reaction, though the p-isomer/o-isomer ratio remained almost unchanged. However, when water-miscible aprotic polar solvents, such as DMF, DMA, NMP, and HMPA, were used at a temperature below 180°C, the p-isomer/o-isomer ratio was markedly increased. Such effects were not noted with other types of solvents.