a-242 a-242 a-242 is an organophosphate nerve agent. it was developed in the soviet union under the foliant program and is one of the group of compounds referred to as novichok agents that were revealed by vil mirzayanov. mirzayanov gives little specific information about a-242, stating that it is highly toxic but no figures are given to compare it to other related agents. it is reportedly a solid rather than a volatile liquid as with most nerve agents, and in order to weaponise it successfully, it had to be milled into a fine powder form that could be dispersed as a dust. a-242 names iupac name methyl-(bis(diethylamino)methylene)phosphonamidofluoridate systematic iupac name 1,1,3,3-tetraethyl-2-guanidine identifiers cas number 2387496-14-0 n 3d model (jsmol) interactive image pubchem cid 146586254 inchi inchi=1s/c10h23fn3op/c1-6-13(7-2)10(12-16(5,11)15)14(8-3)9-4/h6-9h2,1-5h3key: wjdiqlitbjemba-uhfffaoysa-n smiles ccn(cc)c(=n(c)(f)=o)n(cc)cc properties chemical formula c10h23fn3op molar mass 251.286 g·mol−1 except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). infobox references legal status a-242 has been added to schedule 1 of the annex on chemicals of the chemical weapons convention as of june 2020, and it has been explicitly named as an example compound for schedule 1.a.15. for chemicals listed in schedule 1, the most stringent declaration and verification measures are in place combined with far-reaching limits and bans on production and use.