Selenolo benzothiophenes

The last step in the synthesis of the sulfur- and selenium-containing psoralen analogues (174) (7/7-thieno[3,2- ][l]benzothiopyran-7-one, 7//-seleno[3,2-/][l]benzothiophen-7-one, 2//-selenolo [3,2- ][l]benzothiopyran-2-one, and 7//-selenolo[3,2-g][ 1 ]benzoselenopyran-7-one) was the poly-phosphoric acid silyl ether (PPSE)-mediated cyclization of benzol-thiophenes or selenophenes shown in Equation (76) <92H(34)lli9>. 

C10H6O2S, Naphtho[1,8-bc]thiete 1,1-dioxide, 42B, 258 CioHsSSe, Naphthoi1,8-cd]-1,2-selenathiole, 43B, 432 CioHsSSe, Selenolo[2,3-b]benzothiophene, 43B, 432 CioHsSSe, Selenolo[3,2-b]benzothiophene, 43B, 432 C1oH7Cl2NO S3, 5-(2,5-Dichloro)-benzsulphonyl-2-sulfamyl-thiophene, 45B, 375... 

The X-ray crystal structures of selenolo[2,3-f>]benzothiophen (752) and of selenolo[3,2-i>]benzothiophen (753) have been determined." ... 

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