({[(8Z)-2-(5-Cyano-6-imino-2-thioxo-3,6-dihydropyrimidin-1(2H)-yl)-5-(diethoxymethyl)-7-oxabicyclo[4.2.0]octa-1,3,5-trien-8-ylidene]amino}methylene)malononitrile AIDS-014305 AIDS014305 NSC256929