What molecule am I?
Chloroform (CHCl3) is a solvent, reagent, refrigerant, and anesthetic with a chemical history that dates back to the 1830s. During that period, at least five scientists synthesized it; but there was much confusion about its chemical formula. Proposed formulas ranged from CH2ClCH2Cl (鈥渃hloric ether鈥� or 1,2-dichloroethane) to C2Cl5 (an impossibility) to C2H2Cl6 (double the actual formula).
By the 1840s, chloroform began to be used as an anesthetic; and by the next decade, it was manufactured on a large scale via the reaction between chloral1 and sodium hydroxide. Chloroform was produced by this process for more than a century; after which, it was replaced by heating methane and/or chloromethane with chlorine. This method produces dichloromethane as well.
An early use of chloroform as a solvent appeared in an 1882 article by Arthur H. Elliott at Columbia College (now Columbia University, New York City). Elliott assessed the solubility of then-new 鈥渘itrosaccharose鈥� (nitrocellulose2) in about 40 solvents available to him and found that at ambient temperature. Chloroform eventually became a widely used industrial and laboratory solvent until recent decades when its hazardous properties (see hazard information table) caused regulatory agencies to restrict its use.
Chloroform alone has little use as a refrigerant; but large quantities of it were used to synthesize chlorodifluoromethane3 (CHClF2), a widely used refrigerant until it was phased out because of its high ozone-depleting and global-warming potentials. Besides CHClF2 synthesis, chloroform, when treated with sodium hydroxide, is used to generate dichlorocarbene4 (:CCl2), which reacts with alkenes in situ to produce dichlorocyclopropane derivatives.
The global chloroform market in 2022 was .
1. CAS Reg. No. 75-87-6.
2. CAS Reg. No. 9004-70-0.
3. CAS Reg. No. 75-45-6.
4. CAS Reg. No. 1605-72-7.
Chloroform hazard information
| Hazard class* | GHS code and hazard statement | |
|---|---|---|
| Acute toxicity, oral, category 4 | H302鈥擧armful if swallowed |  |
| Skin corrosion/irritation, category 2 | H315鈥擟auses skin irritation |  |
| Serious eye damage/eye irritation, category 2A | H319鈥擟auses serious eye irritation | |
| Acute toxicity, inhalation, category 3 | H331鈥擳oxic if inhaled | |
| Specific target organ toxicity, single exposure, narcotic effects, category 3 | H336鈥擬ay cause drowsiness or dizziness | |
| Carcinogenicity, category 2 | H351鈥擲uspected of causing cancer |  |
| Reproductive toxicity, category 2 | H361鈥擲uspected of damaging fertility or the unborn child | |
| Specific target organ toxicity, repeated exposure, oral, category 1 | H372鈥擟auses damage to organs (liver, kidney) through prolonged or repeated exposure if swallowed | |
| Short-term (acute) aquatic hazard, category 3 | H402鈥擧armful to aquatic life | |
*Globally Harmonized System (GHS) of Classification and Labeling of Chemicals.听.
Xanomeline1 is a muscarinic acetylcholine receptor agonist that was originally developed in the 1990s as a possible Alzheimer's disease treatment. Trospium chloride2 is a 1970s-era muscarinic antagonist used to treat overactive bladder. How are these two drugs connected?
During trials on xanomeline, Neil C. Bodick and colleagues at Eli Lilly (Indianapolis) and several other institutions observed that the drug associated with Alzheimer鈥檚. But Lilly shelved xanomeline research because of its gastrointestinal side effects.
In 2012, Andrew Miller, recognizing that xanomeline still had promise, licensed it from Lilly to start a new company, Karuna Therapeutics (Boston), for developing it to treat schizophrenia. To combat the gastrointestinal problems, Steven M. Paul and co-workers at Karuna , which does not cross the blood鈥揵rain barrier but blocks muscarinic receptors in the gut. The drug combination, called KarXT, has undergone clinical trials and was submitted for approval by the US Food and Drug Administration last November.
1. CAS Reg. No. 131986-45-3.
2. CAS Reg. No. 10405-02-4.
Molecules of the Future
Once a month we bring you a newly discovered or developed molecule(s) that has important implications for the future of chemistry or society in general. Look for it the third week of each month.听Learn more about this month's Molecules of the Future.
We're looking for more molecules of the future!
Do you have a suggestion for the next molecule of the future? Send your idea to MOTW.
This molecule was suggested by a reader. We present听almost all of the molecules suggested by our readers.听If you have a molecule you would like us to consider, please send us a message. And thank you for your interest in Molecule of the Week! 鈥擡d.
听
Chloroform fast facts
| CAS Reg. No. | 67-66-3 |
| SciFindern name | Methane, trichloro- |
| Empirical formula | CHCl3 |
| Molar mass | 119.38 g/mol |
| Appearance | Colorless liquid |
| Boiling point | 61 掳C |
| Water solubility | 8 g/L (20 掳C) |
, the most authoritative and comprehensive source for chemical information.
Molecule of the Week needs your suggestions!
If your favorite molecule is not in our听archive, please send us a message. The molecule can be notable for its current or historical importance or for any quirky reason. Thank you!
Stay Ahead of the Chemistry Curve
Learn how ACS can help you stay ahead in the world of chemistry.
