A new synthesis of thiophenes and thiapyrans

Part IV. Thiophenes and thiapyrans from naphthalene thiols
  • B. D. Tilak


4:5-Benzothionaphthene (II) was obtained by theα-cyclization ofβ-naphthylω-dimethoxyethyl sulphide (I), and the hitherto unknown naphtho-(1′:8′-bc)-thiapyran (IV) by theperi-cyclization ofα-naphthylω-dimethoxyethyl sulphide (III).

Naphthalene-1:5-dithiol was obtained in 85% yield by an improved method. Condensation of naphthalene-1:5 and 2:6-dithiols with two molecules of bromoacetaldehyde dimethyl acetal gave (VIII) and (XI). The former cyclized in theperi-positions to give “1:6-thiapyrene” (IX) which was orange in colour, and the latter cyclized in theα-positions to give 4:5, 5′:4′-dithionaphthene (XII), an isoster of chrysene which was colourless. Chrysene and (XII) gave similar absorption spectra, which were markedly different from the absorption spectrum of (IX).


Thiophene Phosphorus Pentoxide Chrysene Dithiol Sodium Iodide 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    Tilak..Proc. Ind. Acad. Sci., 1950,32A, 390.Google Scholar
  2. 1a.
    Sunthankar and Tilak.., 396.Google Scholar
  3. 2.
    Mayer,et al...Annalen, 1931,488, 259.Google Scholar
  4. 3.
    Szmuszkovicz and Modest..J. A. C. S., 1950,72, 571.CrossRefGoogle Scholar
  5. 4.
    .. See following paper.Google Scholar
  6. 5.
    Renard..Bull. Soc. Chim., 1889,3 (3), 958; 1891,5, 278.Google Scholar
  7. 5a.
    Anschutz and Rodins..Ber., 1914,47, 2733.Google Scholar
  8. 5b.
    Horton..J. Org. Chem., 1949,14, 761.CrossRefGoogle Scholar
  9. 6.
    Albenga and Corbellini..Gazz. chim. Ital., 1931,61, 111.Google Scholar
  10. 7.
    Leuckart..J. pr. Chem., 1890,41, 189.Google Scholar

Copyright information

© Indian Academy of Sciences 1951

Authors and Affiliations

  • B. D. Tilak
    • 1
  1. 1.Department of Chemical TechnologyUniversity of BombayIndia

Personalised recommendations