Reductive methylation perylene

Figure 4. X-ray diffraction pattern (Cu) of reductively methylated perylene following melting and resolidification. Sharp peaks are at 10-15 and 5.13 A, and broad peaks are at 6.55, 4.36, and 2.15 A.

Thus, the C-l/C-q model self-consistently accounts for the three NOE experiments, and the C-3/C-q model does not. The dominant regioisomer of the reductive methylation of perylene has methyl groups at C-l and the adjacent nonprotonated carbon (see Scheme II). 

DECACYCLENE CHEMISTRY. Unlike perylene, which consumes 2 mol of K per mole of perylene, decacyclene consumes between 2.2 and 3.0 mol of K per mole of decacyclene. As with perylene, we wanted to determine if reductive methylation could yield a product with a methyl group on a quaternary carbon, as in the C-3/C-q dimethyldihydrodecacyclene isomer depicted in Scheme III. 

The reduction of three polynuclear aromatic compounds, namely, perylene, decacyclene, and dibenzothiophene, with potassium metal in tetrahydrofuran at 25 °C, followed by quenching with alkyl iodides, was investigated. With perylene, a dianion was obtained, which on reaction with methyl iodide added two methyl groups the main re-gioisomer had one methyl group on C-l and one methyl group on the adjacent nonprotonated carbon, C-14. The reductive alkylation of decacyclene also led to alkyl groups on quaternary carbon atoms. The reduction of dibenzothiophene led to a loss of sulfur and proton uptake from solvent to yield biphenyl as the product after 24 h of reduction. 

The most widely used reductive degradation methods are zinc distillation and sodium amalgam reduction. Fused aromatic structures (methyl substituted naphthalene, anthracene, pyrene, and perylene) are the major digest products of this reduction of humic substances. 

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