VR (nerve agent): Difference between revisions

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 428728291

| Name = VR

| PIN = ''S''-[2-(Diethylamino)ethyl] ''O''-(2-methylpropyl) methylphosphonothioate

| CASNo_Ref = {{cascite|correct|??}}

| CASNo = 159939-87-4

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = LG34LSI9IU

| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}

| ChemSpiderID = 154981

| ChEBI = 140422

| InChI = 1/C11H26NO2PS/c1-6-12(7-2)8-9-16-15(5,13)14-10-11(3)4/h11H,6-10H2,1-5H3

| InChIKey = MNLAVFKVRUQAKW-UHFFFAOYAF

| StdInChI_Ref = {{stdinchicite|changed|chemspider}}

| StdInChI = 1S/C11H26NO2PS/c1-6-12(7-2)8-9-16-15(5,13)14-10-11(3)4/h11H,6-10H2,1-5H3

| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}

| StdInChIKey = MNLAVFKVRUQAKW-UHFFFAOYSA-N

{{Chemical agents sidebar |nerve}}

'''VR''' ('''Russian VX''', '''VXr''', '''Soviet V-gas''', '''[[GosNIIOKhT|GOSNIIOKhT]] substance No. 33''', '''Agent "November"''') is a "V-series" [[Chemical weapon|unitary]]

[[nerve agent]] closely related (it is an [[isomer]]) to the better-known [[VX (nerve agent)|VX nerve agent]].<ref>Fedorov L. A. Undeclared Chemical War in Russia. Moscow, 1995 (Russian)</ref> It became a prototype for the series of [[Novichok agents]]. According to chemical weapons expert [[Jonathan B. Tucker|Jonathan Tucker]], the first binary formulation developed under the Soviet Foliant program was used to make '''Substance 33''', differing from VX only in the alkyl substituents on its nitrogen and oxygen atoms. "This weapon was given the code name Novichok."<ref>{{cite journal |url=https://cen.acs.org/articles/96/i12/Nerve-agent-attack-on-spy-used-Novichok-poison.html |title=Nerve agent attack on spy used 'Novichok' poison |date=19 March 2018 |volume=96 |issue= 12 |page=3 |journal=Chemical & Engineering News |first=Mark |last=Peplow |publisher=[[American Chemical Society]] |access-date=28 March 2018}}</ref>

== History ==

The development of VR started in 1957, after the [[Soviet Union]] obtained information about detection of high level of toxicity in phosphorylthiocholines<ref>{{cite book|last=Major General Antonov|first=Nikolai S.|title=Khimicheskoe Oruzhiye na Rubezhe Dvukh Stoletii|script-title=ru:Химическое оружие на рубеже двух столетий |trans-title=Chemical Weapons at the Turn of the Century|language=ru|url=http://documents.theblackvault.com/documents/weapons/2009-03137-F.pdf|page=22|location=Moscow|publisher=Progress|year=1994|isbn=5-01-004462-5<!-- ISBN printed without 5 in the book, but validates with the 5 added and is given on https://search.rsl.ru/en/record/01001704817 and 5 indicates Russia, so that makes sense-->|lccn=96160418}}</ref> (the same year [[Lars-Erik Tammelin]] published his first articles on fluorophosphorylcholines and phosphorylthiocholines in [[Acta Chemica Scandinavica]]) by a team from the [[Soviet Union's Scientific Research Institute]] No. 42 (NII-42). Sergei Zotovich Ivin, Leonid Soborovsky, and Iya Danilovna Shilakova jointly developed this analogue of VX. They completed their work in 1963 and were later awarded the [[Lenin Prize]] for their achievement.<ref>Tucker, J. B.; War of Nerves; Anchor Books; New York; 2006; pp 181-182.</ref> A [[binary weapon]] comprising two less toxic precursors which mixed during flight to form Substance 33 was later developed by a team led by Nikolai Kuznetsov.<ref>Vil S. Mirzayanov. State Secrets. An Insider's Chronicle of the Russian Chemical Weapons Program. (2009) pp166-168. {{ISBN|978-1-4327-2566-2}}</ref>

In 1972 the Soviets opened [[Cheboksary Khimprom]], a manufacturing plant for VR in [[Novocheboksarsk]].<ref>Tucker, J. B.; War of Nerves; Anchor Books; New York; 2006; pp 230–231.</ref> All facilities in [[USSR]] produced 15,557 tons of VR according to their declaration to the [[Organisation for the Prohibition of Chemical Weapons]] (OPCW),<ref>{{Cite web|url=http://www.cbwinfo.com/Chemical/Nerve/VR.shtml|title=Factsheets on Chemical and Biological Warfare Agents}}</ref> although most if not all of this has now been destroyed under disarmament treaties.<ref>{{Cite web|url=http://www.fas.org/nuke/guide/russia/cbw/cw.htm|title=Chemical Weapons – Russian / Soviet Nuclear Forces}}</ref>

== Comparison to VX ==

VR has similar lethal dose levels to VX (between 10–50&nbsp;mg), as well as being similar in appearance.<ref>{{Cite web|url=https://www.acs.org/content/acs/en/molecule-of-the-week/archive/v/vr.html|title=VR|website=American Chemical Society}}</ref> However, due to usage of diethylamino radicals instead of diisopropylamino it is more prone to decomposition. The former are worse at sterically protecting the nitrogen atom from attacking either phosphorus or the α-carbon atom adjacent to sulfur than the latter. According to UK [[Defence Science and Technology Laboratory]] Detection Department scientists Robin M. Black and John M. Harrison, chemical stability was an important factor why of all the similarly toxic phosphorylthiocholines, ethyl N-2-diisopropylaminoethyl methylphosphonothiolate in particular (now known as VX), was weaponized in the West.<ref>Black R.M., Harrison J.M. The chemistry of organophosphorus chemical warfare agents. Chapter 10 of The chemistry of organophosphorus compounds. Volume 4, Ter- and quinque-valent phosphorus acids and their derivatives. (1996) {{Cite book|doi=10.1002/9780470682531.pat0070|isbn=978-0-471-95706-5|chapter=The Chemistry of Organophosphorus Chemical Warfare Agents|title=PATai's Chemistry of Functional Groups|year=2009|last1=Black|first1=R. M.|last2=Harrison|first2=J. M.}}</ref>

According to Russian CW developer [[Vil Mirzayanov]], in the late 1980s a group of [[GosNIIOKhT]] chemists led by Georgiy Drozd prepared a scientific report that Substance 33 had much lower shelf life than VX. The report, writes Mirzayanov, caused 'panic' in the institute top management and the military representative office, and later was met with administrative resistance. This finding was independently verified by another chemist Igor Revelskiy but his report wasn't approved either.<ref>{{Cite book | url=https://books.google.com/books?id=ldpNPgAACAAJ |title = State Secrets: An Insider's Chronicle of the Russian Chemical Weapons Program|isbn = 978-1-4327-1923-4|last1 = Mirzayanov|first1 = Vil S.|date = December 2008| publisher=Outskirts Press, Incorporated }}</ref>

Following the [[poisoning of Sergei and Yulia Skripal]], former head of the GosNIIOKhT security department Nikolay Volodin said in an interview to [[Novaya Gazeta]] that Substance 33 was decomposing too quickly in combat conditions, and implied that this fact may have influenced the decision to continue research on the [[Novichok]] program.<ref>{{Cite web|url=https://www.novayagazeta.ru/articles/2018/03/23/75908-demonstrativnoe-ubiystvo-mozhno-bylo-organizovat-prosche|title="Новичок" — это слишком для одного Скрипаля"|date=March 23, 2018|website=Новая газета - Novayagazeta.ru}}</ref>

== Toxicity ==

Both agents have similar symptoms and method of action to other nerve agents that act on [[cholinesterase]], and treatment remains the same. However, the window for effectively treating second generation V series [[seizure]]s is shorter, as they rapidly denature the acetylcholinesterase protein in a similar manner to [[soman]], making treatment with the standard nerve gas antidote [[pralidoxime]] ineffective unless it is given very soon after exposure.{{citation needed|date=March 2018}} Pre-treatment with [[pyridostigmine]] prior to exposure, and treatment with other drugs such as [[atropine]] and [[diazepam]] after exposure, will reduce symptoms of nerve agent toxicity but may not be sufficient to prevent death if a large dose of nerve agent has been absorbed. In addition to the standard seizures, some of the second generation V series agents are known to cause [[coma]]s.

== See also ==

* [[A-234 (nerve agent)]]

* [[Novichok agent]]

== References ==

<references />

{{Neurotoxins}}

{{Acetylcholine metabolism and transport modulators}}

[[Category:Acetylcholinesterase inhibitors]]

[[Category:V-series nerve agents]]

[[Category:Diethylamino compounds]]

[[Category:Soviet chemical weapons program]]

[[Category:Isobutyl esters]]