2-Chloro-10-((2-chloro-5-oxido-10,11-dihydrodibenzo[b,f]thiepin-10-yl)dithio)-10,11-dihydrodibenzo[b,f]thiepine 5-oxide AIDS-139398 AIDS139398 Bis(2-chloro-5-oxido-10,11-dihydrodibenzo[b,f]thiepin-10-yl) disulfide NSC648492