Phosgene oxime: Difference between revisions

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not a blister agent, as stated in nettle agent
 
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| Watchedfields = changed
| Watchedfields = changed
| verifiedrevid = 464204793
| verifiedrevid = 464204793
| ImageFileL1 = Phosgene-oxime-2D.png
| ImageFile1 = Phosgene-oxime-2D.png
⚫
| ImageName1 = Full structural formula
| ImageSizeL1 =
⚫
| ImageFile2 = Phosgene-oxime-HF-3D-vdW.png
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| ImageNameL1 = Full structural formula
⚫
| ImageName2 = Space-filling model
⚫
| ImageFileR1 = Phosgene-oxime-HF-3D-vdW.png
| ImageCaption2 = {{legend|black|[[Carbon]], C}}{{legend|white|[[Hydrogen]], H}}{{legend|red|[[Oxygen]], O}}{{legend|blue|[[Nitrogen]], N}}{{legend|lime|[[Chlorine]], Cl}}
| ImageSizeR1 =
⚫
| ImageNameR1 = Space-filling model
| PIN = 1,1-Dichloro-''N''-hydroxymethanimine
| PIN = 1,1-Dichloro-''N''-hydroxymethanimine
| OtherNames = {{ubl|CX|Dichloroformaldehyde oxime|Dichloroformaldoxime|Dichloroformoxime|Hydroxycarbonimidic dichloride}}
| OtherNames = dichloroformaldoxime, dichloroformoxime, hydroxycarbonimidic dichloride, CX, dichloroformaldehyde oxime
|Section1={{Chembox Identifiers
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
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}}
}}
|Section2={{Chembox Properties
|Section2={{Chembox Properties
| Formula = {{chem2|Cl2CNOH}}
| C=1 | H=1 | N=1 | O=1 | Cl=2
| C=1 | H=1 | N=1 | O=1 | Cl=2
| Appearance = colorless or white solid
| Appearance = colorless or white solid
| Density =
| Density =
| Odor = Strong, disagreeable and irritating
| MeltingPtC = 35 to 40
| MeltingPtC = 35 to 40
| MeltingPt_ref = <ref name="ATSDR">[http://www.atsdr.cdc.gov/MHMI/mmg167.html ATSDR Medical Management Guidelines for Phosgene Oxime]</ref>
| MeltingPt_ref = <ref name="ATSDR">[https://web.archive.org/web/20030802032513/http://www.atsdr.cdc.gov/MHMI/mmg167.html ATSDR Medical Management Guidelines for Phosgene Oxime]</ref>
| BoilingPtC = 128
| BoilingPtC = 128
| BoilingPt_ref = <ref name="ATSDR" />
| BoilingPt_ref = <ref name="ATSDR" />
| Solubility = 70%<ref name="ATSDR" /> }}
| Solubility = 70%<ref name="ATSDR" /> }}
|Section3={{Chembox Hazards
|Section7={{Chembox Hazards
| MainHazards = Highly toxic
| MainHazards = Highly toxic
| FlashPt =
| FlashPt =
| AutoignitionPt =
| AutoignitionPt =
}}
}}
| Section9 = {{Chembox Related
| OtherCompounds = {{ubl|[[Formaldoxime]]|[[Phosgene]]|[[Oxime]]}}
}}
}}
}}


'''Phosgene oxime''', or '''CX''', is an [[organic compound]] with the [[chemical formula|formula]] Cl<sub>2</sub>CNOH. It is a potent [[chemical weapon]], specifically a [[nettle agent]]. The compound itself is a colorless solid, but impure samples are often yellowish liquids. It has a strong, disagreeable and irritating odor. It is used as a reagent in [[organic chemistry]].<ref>{{cite book |doi=10.1002/047084289X.rn02011|chapter=Dichloroformaldehyde Oxime |title=Encyclopedia of Reagents for Organic Synthesis |year=2017 |last1=Wang |first1=Xinyan |last2=Chen |first2=Wenwen |pages=1–2 |isbn=9780470842898 }}</ref>
'''Phosgene oxime''', or '''CX''', is an [[organic compound]] with the [[chemical formula|formula]] {{chem2|Cl2C\dN\sOH|auto=1}}. It is a potent [[chemical weapon]], specifically a [[nettle agent]]. The compound itself is a colorless solid, but impure samples are often yellowish liquids. It has a strong, disagreeable and irritating odor. It is used as a reagent in [[organic chemistry]].<ref>{{cite book |doi=10.1002/047084289X.rn02011|chapter=Dichloroformaldehyde Oxime |title=Encyclopedia of Reagents for Organic Synthesis |year=2017 |last1=Wang |first1=Xinyan |last2=Chen |first2=Wenwen |pages=1–2 |isbn=9780470842898}}</ref>


==Preparation and reactions==
==Preparation and reactions==
Phosgene oxime can be prepared by [[reduction (chemistry)|reduction]] of [[chloropicrin]] using a combination of [[tin]] metal and [[hydrochloric acid]] as the source of the active hydrogen reducing acent:
Phosgene oxime can be prepared by [[reduction (chemistry)|reduction]] of [[chloropicrin]] using a combination of [[tin]] metal and [[hydrochloric acid]] as the source of the [[active hydrogen]] [[reducing agent]]:
:{{chem2|Cl3CNO2 + 4 [H] -> Cl2C\dN\sOH + HCl + H2O}}
:{{chem2|Cl3CNO2 + 4 [H] → Cl2C\dN\sOH + [[Hydrogen chloride|HCl]] + H2O}}


The observation of a transient violet color in the reaction suggests intermediate formation of [[trichloronitrosomethane]] (Cl<sub>3</sub>CNO). Early preparations, using stannous chloride as the reductant, also started with chloropicrin.<ref>{{ cite journal |author1=Prandtl, W. |author2=Dollfus, W. | title = Über das Trichlor-nitroso-methan, das Dichlor-formoxim (Phosgen-oxim) und einige ihrer Derivate, 2. Mitteilung: Über zwei neue Derivate der Kohlensäure | journal = Berichte der Deutschen Chemischen Gesellschaft | year = 1932 | volume = 65B |issue=5 | pages = 754–9 | doi = 10.1002/cber.19320650515 }}</ref>
The observation of a transient violet color in the reaction suggests intermediate formation of [[trichloronitrosomethane]] (Cl<sub>3</sub>CNO). Early preparations, using stannous chloride as the reductant, also started with chloropicrin.<ref>{{cite journal |author1=Prandtl, W. |author2=Dollfus, W. | title = Über das Trichlor-nitroso-methan, das Dichlor-formoxim (Phosgen-oxim) und einige ihrer Derivate, 2. Mitteilung: Über zwei neue Derivate der Kohlensäure | journal = Berichte der Deutschen Chemischen Gesellschaft | year = 1932 | volume = 65B |issue=5 | pages = 754–9 | doi = 10.1002/cber.19320650515}}</ref>


The compound is electrophilic and thus sensitive to nucleophiles, including bases, which destroy it:
The compound is [[electrophilic]] and thus sensitive to [[nucleophiles]], including [[Base (chemistry)|bases]], which destroy it:
:{{chem2|Cl2CNOH + 2 NaOH -> CO2 + NH2OH + 2 NaCl + H2O}}
:{{chem2|Cl2CNOH + 2 [[Sodium hydroxide|NaOH]] → [[Carbon dioxide|CO2]] + [[Hydroxylamine|NH2OH]] + 2 [[Sodium chloride|NaCl]] + H2O}}


Phosgene oxime has been used to prepare heterocycles that contain N-O bonds, such as [[isoxazole]]s.<ref>{{cite journal |doi=10.1021/jo502634h|title=Tandem Synthesis of 3-Chloro-4-iodoisoxazoles from 1-Copper(I) Alkynes, Dichloroformaldoxime, and Molecular Iodine|year=2015|last1=Chen|first1=Wenwen|last2=Zhang|first2=Jianlan|last3=Wang|first3=Bo|last4=Zhao|first4=Zhouxing|last5=Wang|first5=Xinyan|last6=Hu|first6=Yuefei|journal=The Journal of Organic Chemistry|volume=80|issue=4|pages=2413–2417|pmid=25594794}}</ref>
Phosgene oxime has been used to prepare [[Heterocyclic compound|heterocycles]] that contain N-O bonds, such as [[isoxazole]]s.<ref>{{cite journal |doi=10.1021/jo502634h|title=Tandem Synthesis of 3-Chloro-4-iodoisoxazoles from 1-Copper(I) Alkynes, Dichloroformaldoxime, and Molecular Iodine|year=2015|last1=Chen|first1=Wenwen|last2=Zhang|first2=Jianlan|last3=Wang|first3=Bo|last4=Zhao|first4=Zhouxing|last5=Wang|first5=Xinyan|last6=Hu|first6=Yuefei|journal=The Journal of Organic Chemistry|volume=80|issue=4|pages=2413–2417|pmid=25594794}}</ref>


Dehydrohalogenation upon contact with mercuric oxide generates [[cyanoformyl chloride]], a reactive nitrile oxide:<ref>{{cite journal |doi=10.1021/JP981262E|title=Unstable Chloronitrile Oxide, ClCNO, and Its Stable Ring Dimer: Generation, Spectroscopy, and Structure|year=1998|last1=Pasinszki|first1=Tibor|last2=Westwood|first2=Nicholas P. C.|journal=The Journal of Physical Chemistry A|volume=102|issue=25|pages=4939–4947|bibcode=1998JPCA..102.4939P}}</ref>
[[Dehydrohalogenation]] upon contact with [[mercuric oxide]] generates [[chlorine fulminate]], a reactive [[nitrile oxide]]:<ref>{{cite journal |doi=10.1021/JP981262E|title=Unstable Chloronitrile Oxide, ClCNO, and Its Stable Ring Dimer: Generation, Spectroscopy, and Structure|year=1998|last1=Pasinszki|first1=Tibor|last2=Westwood|first2=Nicholas P. C.|journal=The Journal of Physical Chemistry A|volume=102|issue=25|pages=4939–4947|bibcode=1998JPCA..102.4939P}}</ref>
:Cl<sub>2</sub>CNOH → ClCNO + HCl
:{{chem2|Cl2CNOH → Cl\sC\tN+\sO− + HCl}}


==Toxicity==
==Toxicity==
Phosgene oxime is classified as a [[blister agent|vesicant]] even though it does not produce blisters.<ref>{{ cite journal | last1 = McManus | first1 = J | last2 = Huebner | first2 = K | title = Vesicants | journal = [[Critical Care Clinics]] | year = 2005 | volume = 21 | issue = 4 | pages = 707–718 | doi = 10.1016/j.ccc.2005.06.005| pmid = 16168310 | url = https://zenodo.org/record/1258826 }}</ref> It is [[toxic]] by inhalation, ingestion, or skin contact. The effects of the poisoning occur almost immediately. No antidote for phosgene oxime poisoning is known. Generally, any treatment is supportive. Typical physical symptoms of CX exposure are as follows:
Phosgene oxime is classified as a [[blister agent|vesicant]] even though it does not produce blisters.<ref>{{cite journal | last1 = McManus | first1 = J | last2 = Huebner | first2 = K | title = Vesicants | journal = [[Critical Care Clinics]] | year = 2005 | volume = 21 | issue = 4 | pages = 707–718 | doi = 10.1016/j.ccc.2005.06.005| pmid = 16168310 | url = https://zenodo.org/record/1258826}}</ref> It is [[toxic]] by inhalation, ingestion, or skin contact. The effects of the poisoning occur almost immediately. No antidote for phosgene oxime poisoning is known. Generally, any treatment is supportive. Typical physical symptoms of CX exposure are as follows:
*Skin: Blanching surrounded by an [[erythema]]tous ring can be observed within 30 seconds of exposure. A [[wheal response|wheal]] develops on exposed skin within 30 minutes. The original blanched area acquires a brown pigmentation by 24 hours. An [[eschar]] forms in the pigmented area by 1 week and sloughs after approximately 3 weeks. Initially, the effects of CX can easily be misidentified as [[mustard gas]] exposure. However, the onset of skin irritation resulting from CX exposure is a great deal faster than mustard gas, which typically takes several hours or more to cause skin irritation.
*Skin: Blanching surrounded by an [[erythema]]tous ring can be observed within 30 seconds of exposure. A [[wheal response|wheal]] develops on exposed skin within 30 minutes. The original blanched area acquires a brown pigmentation by 24 hours. An [[eschar]] forms in the pigmented area by 1 week and sloughs after approximately 3 weeks. Initially, the effects of CX can easily be misidentified as [[mustard gas]] exposure. However, the onset of skin irritation resulting from CX exposure is a great deal faster than mustard gas, which typically takes several hours or more to cause skin irritation.
*Eyes: Eye examination typically demonstrates [[conjunctivitis]], [[lacrimation]], lid edema, and [[blepharospasm]] after even minute exposures. More severe exposures can result in [[keratitis]], [[iritis]], [[corneal]] perforation, and [[blindness]].
*Eyes: Eye examination typically demonstrates [[conjunctivitis]], [[lacrimation]], lid edema, and [[blepharospasm]] after even minute exposures. More severe exposures can result in [[keratitis]], [[iritis]], [[corneal]] perforation, and [[blindness]].

Latest revision as of 19:56, 22 April 2024

Phosgene oxime
Full structural formula
Space-filling model
  Carbon, C
  Hydrogen, H
  Oxygen, O
  Nitrogen, N
  Chlorine, Cl
Names
Preferred IUPAC name
1,1-Dichloro-N-hydroxymethanimine
Other names
  • CX
  • Dichloroformaldehyde oxime
  • Dichloroformaldoxime
  • Dichloroformoxime
  • Hydroxycarbonimidic dichloride
Identifiers
3D model (JSmol)
ChemSpider
UNII
  • InChI=1S/CHCl2NO/c2-1(3)4-5/h5H checkY
    Key: JIRJHEXNDQBKRZ-UHFFFAOYSA-N checkY
  • InChI=1/CHCl2NO/c2-1(3)4-5/h5H
    Key: JIRJHEXNDQBKRZ-UHFFFAOYAP
  • Cl/C(Cl)=N\O
Properties
Cl2CNOH
Molar mass 113.93 g·mol−1
Appearance colorless or white solid
Odor Strong, disagreeable and irritating
Melting point 35 to 40 °C (95 to 104 °F; 308 to 313 K)[1]
Boiling point 128 °C (262 °F; 401 K)[1]
70%[1]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Highly toxic
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Phosgene oxime, or CX, is an organic compound with the formula Cl2C=N−OH. It is a potent chemical weapon, specifically a nettle agent. The compound itself is a colorless solid, but impure samples are often yellowish liquids. It has a strong, disagreeable and irritating odor. It is used as a reagent in organic chemistry.[2]

Preparation and reactions[edit]

Phosgene oxime can be prepared by reduction of chloropicrin using a combination of tin metal and hydrochloric acid as the source of the active hydrogen reducing agent:

Cl3CNO2 + 4 [H] → Cl2C=N−OH + HCl + H2O

The observation of a transient violet color in the reaction suggests intermediate formation of trichloronitrosomethane (Cl3CNO). Early preparations, using stannous chloride as the reductant, also started with chloropicrin.[3]

The compound is electrophilic and thus sensitive to nucleophiles, including bases, which destroy it:

Cl2CNOH + 2 NaOH → CO2 + NH2OH + 2 NaCl + H2O

Phosgene oxime has been used to prepare heterocycles that contain N-O bonds, such as isoxazoles.[4]

Dehydrohalogenation upon contact with mercuric oxide generates chlorine fulminate, a reactive nitrile oxide:[5]

Cl2CNOH → Cl−C≡N+−O− + HCl

Toxicity[edit]

Phosgene oxime is classified as a vesicant even though it does not produce blisters.[6] It is toxic by inhalation, ingestion, or skin contact. The effects of the poisoning occur almost immediately. No antidote for phosgene oxime poisoning is known. Generally, any treatment is supportive. Typical physical symptoms of CX exposure are as follows:

  • Skin: Blanching surrounded by an erythematous ring can be observed within 30 seconds of exposure. A wheal develops on exposed skin within 30 minutes. The original blanched area acquires a brown pigmentation by 24 hours. An eschar forms in the pigmented area by 1 week and sloughs after approximately 3 weeks. Initially, the effects of CX can easily be misidentified as mustard gas exposure. However, the onset of skin irritation resulting from CX exposure is a great deal faster than mustard gas, which typically takes several hours or more to cause skin irritation.
  • Eyes: Eye examination typically demonstrates conjunctivitis, lacrimation, lid edema, and blepharospasm after even minute exposures. More severe exposures can result in keratitis, iritis, corneal perforation, and blindness.
  • Respiratory: Irritation of the mucous membranes may be observed on examination of the oropharynx and nose. Evidence of pulmonary edema, including rales and wheezes, may be noted on auscultation. Pulmonary thromboses are prominent features of severe CX exposure.
  • Gastrointestinal: Some animal data suggest that CX may cause hemorrhagic inflammatory changes in the GI tract.

References[edit]

  1. ^ a b c ATSDR Medical Management Guidelines for Phosgene Oxime
  2. ^ Wang, Xinyan; Chen, Wenwen (2017). "Dichloroformaldehyde Oxime". Encyclopedia of Reagents for Organic Synthesis. pp. 1–2. doi:10.1002/047084289X.rn02011. ISBN 9780470842898.
  3. ^ Prandtl, W.; Dollfus, W. (1932). "Über das Trichlor-nitroso-methan, das Dichlor-formoxim (Phosgen-oxim) und einige ihrer Derivate, 2. Mitteilung: Über zwei neue Derivate der Kohlensäure". Berichte der Deutschen Chemischen Gesellschaft. 65B (5): 754–9. doi:10.1002/cber.19320650515.
  4. ^ Chen, Wenwen; Zhang, Jianlan; Wang, Bo; Zhao, Zhouxing; Wang, Xinyan; Hu, Yuefei (2015). "Tandem Synthesis of 3-Chloro-4-iodoisoxazoles from 1-Copper(I) Alkynes, Dichloroformaldoxime, and Molecular Iodine". The Journal of Organic Chemistry. 80 (4): 2413–2417. doi:10.1021/jo502634h. PMID 25594794.
  5. ^ Pasinszki, Tibor; Westwood, Nicholas P. C. (1998). "Unstable Chloronitrile Oxide, ClCNO, and Its Stable Ring Dimer: Generation, Spectroscopy, and Structure". The Journal of Physical Chemistry A. 102 (25): 4939–4947. Bibcode:1998JPCA..102.4939P. doi:10.1021/JP981262E.
  6. ^ McManus, J; Huebner, K (2005). "Vesicants". Critical Care Clinics. 21 (4): 707–718. doi:10.1016/j.ccc.2005.06.005. PMID 16168310.

External links[edit]

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