| Abstract: | Naphtho[2,1-b]benzothiophene has been synthesized unequivocally by the ring closure of 2-phenylmercapto-1-tetralone, followed by dehydrogenation of the resulting dihydro derivative. The other isomeric naphthobenzothiophenes have been prepared by modifications of known methods and their ultraviolet absorption spectra have been compared. Condensation of α-naphthol with 2-chlorocyclohexanone leads to 7,8,9,10-tetrahydronaphtho-[1,2--6]benzofuran, which can be readily dehydrogenated with selenium to naphtho[1,2-b]-benzofuran. The ultraviolet spectra of the naphthobenzofurans are reported, and compared to their sulfur analogs. |
