VP (3,3,5-Trimethylcyclohexyl 3-pyridyl methylphosphonate), also known as EA-1511, is an extremely toxic organophosphate nerve agent of the V-series.John B. Samuel; Elwin C. Penski; John J. Callahan. Chemical Branch Research Division. ARCSL-SP-83015 - PHYSICAL PROPERTIES OF STANDARD AGENTS, CANDIDATE AGENTS. Commander, Chemical Systems Laboratory; ATTN: DRDAR-CLB-CP - Aberdeen Proving Ground, Maryland 21010. June 1983
Agent VP belongs to a class of organophosphates known as 3-pyridyl phosphonates. These agents are extremely potent acetylcholinesterase inhibitors.F. N. Marzulli. Medical Laboratories Special Report No. 75 - A comparison of toxic properties of the V-agents with GB. CMLRE-ML-52. December 1955
Synthesis Methylphosphonic dichloride and triethylamine are dissolved in benzene. 3,3,5-Trimethylcyclohexanol is then slowly added while stirring and cooling. The reaction temperature is maintained at 15 °C. The mixture is then heated to 40 °C for 1 hour. A benzene solution of 3,3,5-trimethylcyclohexyl methylphosphonochloridate is formed.
Triethylamine is then added to reaction mixture and 3-pyridol is added slowly while stirring and cooling. The reaction temperature is maintained at 35 °C. The mixture is then stirred for 1 hour at room temperature. The mixture is washed with a sodium hydroxide solution and water. The solvent is then removed by distillation at reduced pressure to yield the final product. The resulting product can be converted to a quaternary salt by reacting with a haloalkane, such as methyl iodide, to produce a water-soluble agent.
See also 2-Ethoxycarbonyl-1-methylvinyl cyclohexyl methylphosphonate A-234 (nerve agent) GV (nerve agent) Ro 3-0422 V-sub x VT (nerve agent)
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