Reductive alkylation dibenzothiophene

Reductive Alkylation of Aromatic Compounds Perylene, Decacyclene, and Dibenzothiophene... 

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. 

Dibenzothiophene Chemistry. Unlike with perylene and deca-cylene, for which reductive alkylation leads simply to the addition of alkyl groups to aromatic compounds, the reductive alkylation of dibenzothiophene can lead to biphenyl (8). This product occurs by the loss of sulfur from dibenzothiophene, followed by the uptake of two protons. Using reaction times of 1-4 h at room temperature, one can isolate a 2-biphenylyl, alkyl sulfide this finding indicates that the anion on sulfur can have some stability. We investigated this situation by performing 2H NMR on a product of the reaction of CD3I with a dibenzothiophene anion solution formed by adding 2 mol of K per mole of dibenzothiophene. 

The results just discussed demonstrate the complexity of the reductive alkylation reaction, even with relatively simple model compounds such as perylene, decacyclene, and dibenzothiophene. 

Dibenzothiophene, 1,2,3,4-tetrahydro-4-keto-synthesis, 4, 905 Dibenzothiophenes alkylation, 4, 724 Birch reduction, 4, 775 C NMR, 4, 11... 

Two novel monoaminodibenzothiophenes, 9b-amino-l,4,4a,9b-tetra-hydrodibenzothiophene (113) and 9b-amino-l,2,3,4,4a,9b-hexayhydro-dibenzothiophene (114) have been synthesized from the corresponding carboxylic acid sulfones 32 and 33 by treatment with sodium methoxide and bromine followed by reduction of the resultant sulfone carbamates with LAH. A -Alkylation of both 113 and 114 gives compounds which possess CNS depressant activity. ... 

---