Optimization phenol hydrogenation

This study shows that the optimization of process conditions could be achieved rapidly by a judicious use of statistics and parallel reactors. A two-level factorial method with two center points was used to limit the total number of experiments to ten. Using two identical high-pressure reactors in parallel further shortened the time required to conduct these experiments. For the model reaction of phenol hydrogenation over a commercially available Pd/C, it was experimentally determined that the optimal yield was 73% at 135 °C, 22.5 bar, and 615 ppm w/w NaOH... 

The compound predicted to have the second greatest potential for swelling nitrile rubber was 2-naphthol. Its optimized interaction with isobutyronitrile is shown in Figure 3. The position of the -OH group in 2-naphthol precludes the simultaneous occurrence of the phenolic hydrogen-nitrile interaction and the much weaker methyl-hydrogen aromatic pi-electron system interaction. 

A classical oxidation reaction that involves radicals is the phenolic oxidative coupling, which is introduced in Section 10.5.A.i. In this reaction, electron transfer from a metal salt to a bis(phenol) leads to intramolecular coupling and a quinone product. The early yields were poor. For example, Barton reacted 219 with potassium ferricyanide [K3(Fe(CN)6l and the product was aryl radical 220. This radical reacted with the second phenolic ring in an intramolecular process that gave 221. Loss of a hydrogen led to the quinone narwedine (222) in a synthesis of galanthamine. 53 jjje yield of 222, however, was only 1.4% under optimal... 

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