In terms of scale, the most important reaction of<unk>  is with hydrogen fluoride to give monochlorodifluoromethane <unk> C-22), a precursor in the production of polytetrafluoroethylene (Teflon): :CHCl3 + 2 HF → CHClF2 + 2 HCl The reaction is conducted in the presence of a catalytic amount of mixed antimony halides. Chlorodifluoromethane is then converted into tetrafluoroethylene, the main precursor to Teflon. Before the Montreal Protocol, chlorodifluoromethane (designated as R-22) was also a popular refrigerant. Solvent The hydrogen attached to carbon in<unk>  participates in hydrogen bonding. Worldwide,<unk>  is also used in pesticide formulations, as a solvent for fats, oils, rubber, alkaloids, waxes, gutta-percha, and resins, as a cleansing agent, grain fumigant, in fire extinguishers, and in the rubber industry. CDCl3 is a common solvent used in NMR spectroscopy. Lewis acid In solvents such as CCl4 and alkanes,<unk>  hydrogen bonds to a variety of Lewis bases. HCCl3 is classified as a hard acid and the ECW model lists its acid parameters as EA = 1.56 and CA = 0.44. Reagent As a reagent,<unk>  serves as a source of the dichlorocarbene :CCl2 group. It reacts with aqueous sodium hydroxide usually in the presence of a phase transfer catalyst to produce dichlorocarbene, :CCl2. This reagent effects ortho-formylation of activated aromatic rings such as phenols, producing aryl aldehydes in a reaction known as the Reimer–Tiemann reaction. Alternatively, the carbene can be trapped by an alkene to form a cyclopropane derivative. In the Kharasch addition,<unk>  forms the CHCl2 free radical in addition to alkenes. Anaesthetic Antique bottles of<unk>  The anaesthetic qualities of<unk>  were first described in 1842 in a thesis by Robert Mortimer Glover, which won the Gold Medal of the Harveian Society for that year. Glover also undertook practical experiments on dogs to prove his theories. Glover further refined his theories and presented them in the thesis for his doctorate at the University of Edinburgh in the summer of 1847. The Scottish obstetrician James Young Simpson was one of the persons required to read the thesis, but later claimed to have never read the thesis and to have come to his conclusions independently. On 4 November 1847, Simpson first discovered the anesthetic qualities of<unk>  on humans. He and two colleagues were entertaining themselves by trying out the effects of various substances, and thus revealed the potential for<unk>  in medical procedures. A few days later, during the course of a dental procedure in Edinburgh, Francis Brodie Imlach became the first person to use<unk>  on a patient in a clinical context. In May 1848, Robert Halliday Gunning made a presentation to the Medico-Chirurgical Society of Edinburgh following a series of laboratory experiments on rabbits that confirmed Glover's findings and also refuted Simpson's claims of originality. However, a knighthood for Simpson, and massive media coverage of the wonders of<unk>  ensured that Simpson's reputation remained high, while the laboratory experiments proving the dangers of<unk>  were largely ignored. Gunning, who became one of the richest persons in Britain, endowed some 13 university scholarships under the names of other scientists rather than his own name. He considered Simpson a charlatan, but one of these prizes is named the Simpson Prize for Obstetrics. It is, however, probably a strange reverse compliment, as arguably any Simpson prize in the wider public eye should be a prize for anaesthesia. By not calling it this he effectively snubbed Simpson whilst at the same time appearing to honour him. The use of<unk>  during surgery expanded rapidly thereafter in Europe. In the 1850s,<unk>  was used by the physician John Snow during the birth of Queen Victoria's last two children. In the United States,<unk>  began to replace ether as an anesthetic at the beginning of the 20th century; however, it was quickly abandoned in favor of ether upon discovery of its toxicity, especially its tendency to cause fatal cardiac arrhythmia analogous to what is now termed "sudden sniffer's death". Some people used<unk>  as a recreational drug or to attempt suicide. One possible mechanism of action for<unk>  is that it increases movement of potassium ions through certain types of potassium channels in nerve cells.<unk>  could also be mixed with other anesthetic agents such as ether to make C.E. mixture, or ether and alcohol to make A.C.E. mixture. In 1848, Hannah Greener, a 15-year-old girl who was having an infected toenail removed, died after being given the anesthetic. Her autopsy establishing the cause of death was undertaken by John Fife assisted by Robert Mortimer Glover. A number of physically fit patients died after inhaling it. However, in 1848 John Snow developed an inhaler that regulated the dosage and so successfully reduced the number of deaths. The opponents and supporters of<unk>  were mainly at odds with the question of whether the complications were solely due to respiratory disturbance or whether<unk>  had a specific effect on the heart. Between 1864 and 1910 numerous commissions in Britain studied<unk> , but failed to come to any clear conclusions. It was only in 1911 that Levy proved in experiments with animals that<unk>  can cause cardiac fibrillation. The reservations about<unk>  could not halt its soaring popularity. Between about 1865 and 1920,<unk>  was used in 80 to 95% of all narcoses performed in the UK and the German-speaking countries. In America, however, there was less enthusiasm for<unk>  narcosis. In Germany, the first comprehensive surveys of the fatality rate during anesthesia were made by Gurlt between 1890 and 1897. In 1934, Killian gathered all the statistics compiled until then and found that the chances of suffering fatal complications under ether were between 1:14,000 and 1:28,000, whereas under<unk>  the chances were between 1:3,000 and 1:6,000. The rise of gas anesthesia using nitrous oxide, improved equipment for administering anesthetics and the discovery of hexobarbital in 1932 led to the gradual decline of<unk>  narcosis. Criminal use<unk>  has reputedly been used by criminals to knock out, daze, or even murder victims. Joseph Harris was charged in 1894 with using<unk>  to rob people. Serial killer H. H. Holmes used<unk>  overdoses to kill his female victims. In September 1900,<unk>  was implicated in the murder of the American businessman William Marsh Rice, the namesake of the institution now known as Rice University.<unk>  was deemed a factor in the alleged murder of a woman in 1991 when she was asphyxiated while sleeping. In 2002, 13-year-old Kacie Woody was sedated with<unk>  when she was abducted by David Fuller and during the time that he had her, before he shot and killed her. In a 2007 plea bargain, a man confessed to using stun guns and<unk>  to sexually assault minors. Use of<unk>  as an incapacitating agent has become widely recognized, bordering on clichéd, due to the popularity of crime fiction authors having criminals use<unk> -soaked rags to render victims unconscious. However, it is nearly impossible to incapacitate someone using<unk>  in this manner. It takes at least five minutes of inhaling an item soaked in<unk>  to render a person unconscious. Most criminal cases involving<unk>  also involve another drug being co-administered, such as alcohol or diazepam, or the victim being found to have been complicit in its administration. After a person has lost consciousness due to<unk>  inhalation, a continuous volume must be administered and the chin must be supported to keep the tongue from obstructing the airway, a difficult procedure typically requiring the skills of an anesthesiologist. In 1865 as a direct result of the criminal reputation<unk>  had gained, medical journal The Lancet offered a "permanent scientific reputation" to anyone who could demonstrate "instantaneous insensibility", i.e. losing consciousness instantaneously, using<unk> .
Chloroform
Triphenylchloroethylene
Chloroethane
Benzene
Diethyl ether
Methanol
Vinyl chloride
Triphenylbromoethylene