Action of Lawesson's reagent on substituted 2‐amino‐1,4‐naphthoquinones: Novel synthesis of benzodiphenoquinone‐bis‐1,3,2‐thiazaphospholine‐2‐sulfide derivatives

1,3,2,4‐Dithiadiphosphetane‐2,4‐disulfide 1 reacts with substituted 2‐amino‐1,4‐naphthoquinons 2a–d to give 4,5,4′,5′‐benzodiphenoquinone‐bis‐1,3,2‐thiazaphospholine‐2‐sulfide derivatives of type 3. Compatible analytical and spectroscopic results were obtained for all the new compounds. A mechanism is proposed to explain the formation of compounds 3. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 488–491, 1999