Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Attempted ring expansion of some benzthiepin derivatives resulted in the formation of benzthiophens such as (3a,b) and (3d,e). A probable mechanism for this transformation has been presented. ... Attempted ring expansion of (1) with AgNO 3 -I 2 or Tl(ONO 2 ) 3 , and the ...