2-((4-Allyldinaphtho[2,1-d:1,2-f][1,3]dithiepin-4-yl)thio)pyridine 4-Allyldinaphtho[2,1-d:1,2-f][1,3]dithiepin-4-yl 2-pyridinyl sulfide AIDS-143578 AIDS143578 NSC664702