Synthesis of 4,6‐Dimethyldibenzothiophene and 1,2,3,4‐Tetrahydro‐4,6‐dimethyldibenzothiophene via Tilak Annulation |
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| Authors: | Xiaoying Xu Xiang Li Anjie Wang Yinyong Sun W Bernd Schweizer Roel Prins |
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| Institution: | 1. State Key Laboratory of Fine Chemicals, Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024, P.?R. China;2. Liaoning Key Laboratory of Petrochemical Technology and Equipments, Dalian 116024, P.?R. China;3. School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001, P.?R. China;4. Institute of Chemical and Bioengineering, ETH Zurich, Wolfgang‐Pauli‐Str. 10, 8093 CH‐Zürich, (phone: +41(44)2528280;5. fax: +41(44)6325490);6. Laboratory for Organic Chemistry, ETH Zurich, Wolfgang‐Pauli‐Str. 10, 8093 CH‐Zürich |
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| Abstract: | 1,2,3,4‐Tetrahydro‐4,6‐dimethyldibenzothiophene was prepared by coupling 2‐bromo‐3‐methylcyclohexanone with 2‐methylbenzenethiol and annulating the product with the aid of polyphosphoric acid. A mixture of 1,2,3,4‐tetrahydro‐4,6‐dimethyldibenzothiophene and 4,6‐dimethyldibenzothiophene was prepared by coupling 2‐bromo‐3‐methylcyclohex‐2‐en‐1‐one with 2‐methylbenzenethiol and annulating the product with the aid of polyphosphoric acid. 2‐Bromo‐3‐methylcyclohexanone was synthesized by conjugate addition of Me3Al to 2‐bromocyclohex‐2‐en‐1‐one with CuBr as catalyst and 2‐bromo‐3‐methylcyclohex‐2‐en‐1‐one by bromination? elimination of 3‐methylcyclohex‐2‐en‐1‐one. 1,2,3,4,4a,9b‐Hexahydro‐4,6‐dimethyldibenzothiophene was prepared by reduction of 1,2,3,4‐tetrahydro‐4,6‐dimethyldibenzothiophene with Zn and CF3COOH. |
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| Keywords: | Tilak annulation Dibenzothiophene 1 2 3 4‐tetrahydro‐4 6‐dimethyl‐ Cyclohex‐2‐en‐1‐one 2‐bromo‐3‐methyl‐ Cyclohexanone 2‐bromo‐3‐methyl‐ Dibenzothiophene 4 6‐dimethyl‐ X‐Ray crystallography |
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