Phenacyl chloride, also commonly known as chloroacetophenone, is a substituted acetophenone. It is a useful building block in

organic chemistry Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; ...

. Apart from that, it has been historically used as a

riot control agent Riot control measures are used by law enforcement, military, paramilitary or security forces to control, disperse, and arrest people who are involved in a riot, unlawful demonstration or unlawful protest. If a riot is spontaneous and irration ...

, where it is designated CN. It should not be confused with

cyanide Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms. In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of ...

, another agent used in chemical warfare, which has the chemical structure CN⁻.

Preparation

Phenacyl chloride is readily available and was first prepared by chlorination of acetophenone vapour. It may also be synthesized by the Friedel-Crafts acylation of

benzene Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, ...

using

chloroacetyl chloride Chloroacetyl chloride is a chlorinated acyl chloride. It is a bifunctional compound, making it a useful building block chemical. Production Industrially, it is produced by the carbonylation of methylene chloride, oxidation of vinylidene chlorid ...

, with an aluminium chloride catalyst: Preparation of phenacyl chloride

Riot control agent

It was investigated, but not used, during the

First First or 1st is the ordinal form of the number one (#1). First or 1st may also refer to: *World record, specifically the first instance of a particular achievement Arts and media Music * 1$T, American rapper, singer-songwriter, DJ, and rec ...

and

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

s. Because of its significantly greater toxicity, it has largely been supplanted by CS gas. Even though CN is still supplied to

paramilitary A paramilitary is an organization whose structure, tactics, training, subculture, and (often) function are similar to those of a professional military, but is not part of a country's official or legitimate armed forces. Paramilitary units carr ...

and police forces in a small pressurized aerosol known as “ Mace” or

tear gas Tear gas, also known as a lachrymator agent or lachrymator (), sometimes colloquially known as "mace" after the early commercial aerosol, is a chemical weapon that stimulates the nerves of the lacrimal gland in the eye to produce tears. In ad ...

, its use is falling as

pepper spray Pepper spray, oleoresin capsicum spray, OC spray, capsaicin spray, or capsicum spray is a lachrymatory agent (a compound that irritates the eyes to cause a burning sensation, pain, and temporary blindness) used in policing, riot control, cr ...

both works and disperses more quickly than CN and is less toxic than CN. The term "Mace" came into being because it was the brand-name invented by one of the first American manufacturers of CN aerosol sprays. Subsequently, in the United States, Mace became

synonymous A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

with tear-gas sprays in the same way that

Kleenex Kleenex is a brand name for a variety of paper-based products such as facial tissue, bathroom tissue, paper towels, tampons, and diapers. Often used informally as a genericized trademark for facial tissue in the United States and Canada, the nam ...

has become strongly associated with

facial tissue Facial tissue and paper handkerchief refers to a class of soft, absorbent, disposable papers that are suitable for use on the face. They are disposable alternatives for cloth handkerchiefs. The terms are commonly used to refer to the type of pap ...

s (a phenomenon known as a

genericized trademark A generic trademark, also known as a genericized trademark or proprietary eponym, is a trademark or brand name that, because of its popularity or significance, has become the generic term for, or synonymous with, a general class of products or ...

). Like CS gas, this compound irritates the

mucous membrane A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...

s (oral, nasal,

conjunctiva The conjunctiva is a thin mucous membrane that lines the inside of the eyelids and covers the sclera (the white of the eye). It is composed of non-keratinized, stratified squamous epithelium with goblet cells, stratified columnar epithelium ...

l and

tracheobronchial The respiratory tract is the subdivision of the respiratory system involved with the process of respiration in mammals. The respiratory tract is lined with respiratory epithelium as respiratory mucosa. Air is breathed in through the nose to th ...

). Sometimes it can give rise to more generalized reactions such as syncope, temporary loss of balance and orientation. More rarely, cutaneous irritating outbreaks have been observed and allergic contact permanent

dermatitis Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can v ...

. At high concentrations, CN may cause corneal epithelial damage and

chemosis Chemosis is the swelling (or edema) of the conjunctiva. The term derives from the Greek ''chem-'' meaning chemical and ''-osis'' meaning denoting action. A chemical reaction, or in this case, a chemical reaction of the conjunctiva which is due t ...

. It has also accounted for at least five deaths, which have resulted from

pulmonary injury A chest injury, also known as chest trauma, is any form of physical injury to the chest including the ribs, heart and lungs. Chest injuries account for 25% of all deaths from traumatic injury. Typically chest injuries are caused by blunt mechanisms ...

and/or

asphyxia Asphyxia or asphyxiation is a condition of deficient supply of oxygen to the body which arises from abnormal breathing. Asphyxia causes generalized hypoxia, which affects primarily the tissues and organs. There are many circumstances that can i ...

TRPA1 Transient receptor potential cation channel, subfamily A, member 1, also known as transient receptor potential ankyrin 1, TRPA1, or The Wasabi Receptor, is a protein that in humans is encoded by the ''TRPA1'' (and in mice and rats by the ''Trpa1' ...

(Transient Receptor Potential-Ankyrin 1) ion channel expressed on

nociceptors A nociceptor ("pain receptor" from Latin ''nocere'' 'to harm or hurt') is a sensory neuron that responds to damaging or potentially damaging stimuli by sending "possible threat" signals to the spinal cord and the brain. The brain creates the sens ...

(especially

trigeminal In neuroanatomy, the trigeminal nerve ( lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and chewing ...

) has been implicated as the site of action for CN, in vivo and in vitro doi=10.1016/j.taap.2008.04.005

References

External links

* {{DEFAULTSORT:Phenacyl Chloride Riot control agents Lachrymatory agents Organochlorides Aromatic ketones Acetophenones