204. BORDENCA, C. (Sloss-Sheffield Steel & Iron Co.). Conversion of Aromatic Hydrocarbons to Aldehydes and Alcohols. United States Patent 2,619,506, Nov. 25, 1952. Chem. Abs., vol. 47, 1953, p. 8091.

Useful saturated cyclic aldehydes and alcohols are prepared by bringing an active Co or Ni hydrogenation catalyst, such as thoria-promoted, freshly reduced Cokieselguhr (I), at 150º-300º and at least 250 p. s. i. pressure into contact with a mixture of H₂, CO, and an unsubstituted or alkyl-substituted aromatic hydrocarbon, until the reaction pressure, which gradually falls during the process, ceases dropping. Thus, H is forced into a high-pressure reaction vessel containing a 175 gm. C₆H₆ and 2gm. (I), until the pressure reaches 1.550 p. s. i. The vessel and its contents are heated to 169º until a reduction in pressure occurs, signifying that the reaction has begun, the pressure is raised to 2.380 p. s. i. with CO, the vessel heated at 230º until another pressure drop occurs, CO again added, and the vessel heated at 260º until the pressure drops; this process is continued 4 hr. until no further pressure drop is apparent, the reaction vessel is cooled, and the gas allowed to escape. Fractional distillation of the product yields cyclohexane and a higher-boiling fraction identified as hexahydrobenzaldehyde as its semicarbzone, m. 170º, and by oxidation with alkaline permanganate to cyclohexanecarboxylic acid.