The synthesis of cis-6,12-Diaryl-6H,12H-dibenzo[b,f][1,5]dithiocin-6,12-imine and cis-6,12-Diphenyl-6,12-epoxy-6H,12H-dibenzo[b,f][1,5]dithiocin

When treated with concentrated hydrochloric acid or heated beyond its melting point, the versatile thioimine 2 2-mercaptobenzhydrylidenamine was unexpectedly converted to the title ring system. Also, this imine can be converted to 3-phenyl-1,2-benzisothiazoles by prolonged exposure to air.