2-Butenoic acid, {3,3'-[dithiobis(2,1-ethandiylimino)]-bis-,} diethyl ester 41834-19-9 AIDS-128928 AIDS128928 Ethyl 6,15-dimethyl-4-oxo-3-oxa-10,11-dithia-7,14-diazaheptadeca-5,15-dien-17-oate NSC308597