Vesicants properties

In a 500 ml. flask, fitted with a reflux condenser, place 53 g. of 1-chloro-methylnaphthalene (Section IV.23), 84 g, of hexamethylenetetramine and 250 ml. of 1 1 acetic acid [CAUTION 1-Chloromethylnaphtha-lene and, to a lesser degree, a-naphthaldehyde have lachrymatory and vesicant properties adequate precautions should therefore be taken to avoid contact with these substances.] Heat the mixture under reflux for 2 hours it becomes homogeneous after about 15 minutes and then an oil commences to separate. Add 100 ml. of concentrated hydrochloric acid and reflux for a further 15 minutes this will hydrolyse any SchifiF s bases which may be formed from amine and aldehyde present and will also convert any amines into the ether-insoluble hydrochlorides. Cool, and extract the mixture with 150 ml. of ether. Wash the ether layer with three 50 ml. portions of water, then cautiously with 50 ml. of 10 per cent, sodium carbonate solution, followed by 50 ml. of water. Dry the ethereal solution with anhydrous magnesium sulphate, remove the ether by distillation on a steam bath, and distil the residue under reduced pressure. Collect the a-naphthaldehyde at 160-162718 mm. the yield is 38 g. 

On diagnosis, determine the need for administration of chemotherapy with vesicant properties. Refer the patient for surgical placement of a central access device. 

Reasonably stable however, in presence of moisture, it hydrolyses rapidly, losing its vesicant property. 

Vesicants produce acidic products including hydrogen chloride (HC1), hydrogen bromide (HBr), or hydrogen fluoride (HF), and ethanolamines, thioglycols, or thioethers when hydrolyzed. Arsenous oxide decomposition products from HL (C03-A010) are toxic and may also have vesicant properties. HL will also produce acetylene at higher pH. 

Sulfur vesicants These agents are insoluble in water and form self-protecting decomposition products at the water/agent interface that prevent hydrolysis of the agent. These decomposition products are stable and some of them have toxic and/or vesicant properties. 

For military purposes, unmodified arsenic vesicants are classified as persistent. However, agent vapors rapidly react with high humidity to lose most of their vesicant properties. Limited solubility slows the hydrolysis of liquid agents. Some hydrolysis products are highly toxic and extremely persistent (see Section 4.4.5). Evaporation rates range from near that of water down to that of light machine oil. 

Although the vesicant properties of arsenical agents can be eliminated during decontamination, arsenic is an element and cannot be destroyed. Residual arsenical compounds may still possess significant toxicity if they enter the body through ingestion, or broken, abraded, or lacerated skin (e.g., penetration of skin by debris). 

Hazardous Decomposition Products Reasonably stable however, in presence of moisture, it hydrolyses rapidly, losing its vesicant property. It also hydrolyses in acidic medium to form HC1 and non-volatile (solid) chlorovinylarsenious oxide, which is less vesicant than Lewisite. Hydrolysis in alkaline medium, as in decontamination with alcoholic caustic or carbonate solution or DS2, produces acetylene and trisodium arsenate (Na3 As 04). Therefore, decontaminated solution would contain toxic arsenic. 

The above reaction is rather remarkable in view of the un-leactivity of the fluorine atom in fluorobromoethane towards many reagents. In order to establish the identity of sesqui-fluoro-H , it was synthesized by an alternative unambiguous method (p. 130). Sesqui-fluoro-H is a mobile liquid, devoid of vesicant properties and non-toxic. The lack of toxicity is understandable since the animal body is probably unable to rupture this C—S link, and hence the compound cannot easily give rise to fluoroacetic acid. 

The group Cl CH2 CH2 N< occurs in the nitrogen mustards which are powerful vesicants, e.g. CH3,N(CH2,CH2C1)2. It was decided therefore to introduce this group into the fluoroacetamide molecule in the hope of combining vesicant properties with the delayed convulsant action of the fluoroacetates. For this purpose N-2 hydroxyethylfluoroacetamide (IV) was prepared by the action of monoethanolamine on methyl fluoroacetate and was readily converted into N-2-chloroethylfluoroacetamide (V) by the action of thionyl chloride ... 

Caution 4-Hexylresorcinol is irritating to the oral mucosa and respiratory tract and to the skin, and its solution in alcohol has vesicant properties. 

Eisleb s original synthetic procedure<7) consisted of treating benzyl cyanide with two molar proportions of sodamide and then condensing the resultant dianion with bis(2-chloroethyl)methylamine (a compound with highly vesicant properties) and converting the intermediate cyanide to the... 

The data base for sulfur mustard contains two developmental toxicity studies in different species, a reproductive bioassay and a standard subchronic toxicity study in one species. In addition, chronic inhalation studies have been conducted on sulfur mustard using rats, mice, guinea pigs and dogs. The principal study identifies a toxic effect that is consistent with the vesicant properties of sulfur mustard. There is no evidence that any other experimental species would be more sensitive to ingested sulfur mustard therefore, additional oral toxicity studies in other species are not considered critical. 

Lewisite [dichloro(2-chlorovinyl)arsine] is an organic arsenical known for its vesicant properties (Rosenblatt et al., 1975). It has a molecular weight of 207.32, vapor pressure of 0.58 mm HG at 25°C, a liquid density of 1,89 g/cm at 25°C, freezing point of -18°C, boiling point of 190°C, and is negligibly soluble in water (DA, 1974). The chemical structure of lewisite is shown below. Lewisite may occur as a trans-isomer and as a cis-isomer. In aqueous solutions, the cis-isomer undergoes photoconversion to the trans-isomer (Clark, 1989). hi the presence of moisture, lewisite is rapidly converted to the more stable but highly toxic lewisite oxide (2-chlorovinylarsenous acid) (Cameron et al., 1946). 

The vesicant properties of lewisite result from direct contact with the skin. Signs of dermal toxicity (pain, inflammation) may be experienced within a minute after exposure. Acute lethality is usually the result of pulmonary injury. Ocular exposure may result in corneal necrosis. Due to its lipophilicity, percutaneous absorption of lewisite is rapid and, at a sufficient exposure, may be associated with systemic toxicity characterized by pulmonary edema, diarrhea, agitation, weakness, hypothermia, and hypotension (lOM, 1993). The threshold for severe systemic toxicity in humans following dermal exposure to lewisite has been estimated at lOmg/kg (9.1-13.4 mg/kg) (Sollman, 1957). 

Methyldichloroarsine was apparently used by the Germans in 1917. Methyldichloroarsine is a colorless liquid of powerful burning odor, which boils at 132°C. It is somewhat soluble in water and is soluble in organic solvents. The specific gravity is 1.838 at 20°C. The vapor pressure at 25° was found to be 10.83 mm Hg. Not only is the material toxic but it has remarkable vesicant properties, comparing favorably with mustard gas in this respect (Bennett and Ddl, 1994). 

Lewisite remains in the environment for about 24 h and it can react with water to form a solid arsenoxide that also has vesicant properties. Affected areas can be treated with strong alkalis to form less harmful substances. Rescue personnel need to wear protective clothing and masks as the risk for secondary contamination is high. Carcasses should be disposed of properly, either buried deeply (away from... 

Of the halogenated sulphides prepared and studied only those with the halogen atoms at the end of the carbon chain have vesicant properties. 

These three chloro-derivatives are obtained as colourless liquids which become faintly green on exposure to daylight. They have odours similar to that of dichloroethyl sulphide, but have no vesicant properties, while their melting points are much lower. 

Each of these contains only two chlorine atoms, like dichloroethyl sulphide. Neither possesses vesicant properties equal to that of )8)8 dichloroethyl sulphide however (Dawson and Lawson). 

Menadione, U5P. Menadione. 2-methyl-1.4-naphtho-quinone. menaphthone. vitamin K3. can be prepared readily by the oxidation of 2-methylnaphthalene with chromic acid. It is a bright yellow, crystalline powder and is nearly odorless. It is affected by sunlight. Menadione is practically insoluble in water, it is soluble in vegetable oils, and I g of it is soluble in about 60 inL of alcohol. The USP/NF cautions that menadione powder is irritating to the respiratory tract and the skin and that an alcoholic solution has vesicant properties. 

Arsenical Vesicants are persistent agents. However, agent vapors rapidly react with high humidity to lose most of their vesicant properties. Limited solubility slows the hydrolysis of liquid agents. 

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