Tert-Amyl alcohol


tert-Amyl alcohol or 2-methylbutan-2-ol, is a branched pentanol.
Historically TAA has been used an anesthetic and more recently used as a recreational drug. TAA is mostly a positive allosteric modulator for GABAA receptors in the same way as ethanol. The effects of TAA and ethanol are similar.
TAA is a colorless liquid with a burning flavor and an unpleasant odor similar to paraldehyde with a hint of camphor. TAA remains as a liquid at room temperature making it a useful alternative solvent to tert-butyl alcohol.

Production

TAA is primarily made by the hydration of 2-methyl-2-butene in the presence of an acidic catalyst.

Natural occurrence

s like TAA are grain fermentation byproducts and therefore trace amounts of TAA are present in many alcoholic beverages. Traces of TAA have been detected in other foods, like fried bacon, cassava and rooibos tea.

History

From about 1880s to 1950s, TAA was used as an anesthetic with the contemporary name of amylene hydrate, but was rarely used solely because of the existence of more efficient drugs. In the 1930s, TAA was mainly used as a solvent for the primary anesthetic tribromoethanol. Like chloroform, TBE is toxic for the liver, so the use of such solutions declined in the 1940s in humans. TBE-TAA-solutions remained in use as short-acting anesthetics for laboratory mice and rats. Such solutions are sometimes called Avertin, which was a brand name for the now discontinued TAA and TBE solution with a volume ratio of 0.5:1 made by the Winthrop Laboratories. Nowadays TAA has found use as a recreational drug.

Use and effects

Ingestion or inhalation of TAA causes euphoria, sedative, hypnotic, and anticonvulsant effects similar to ethanol. When ingested, the effects of TAA may begin in about 30 minutes and can last up to 1–2 days. 2–4 grams of TAA causes unconsciousness. About 100 g of ethanol induces a similar level of unconsciousness.

Overdose and toxicity

The smallest known dose of TAA that has killed a person is 30 ml.
An overdose produces symptoms similar to alcohol poisoning and is a medical emergency due to the sedative/depressant properties which manifest in overdose as potentially lethal respiratory depression. The oral in rats is 1 g/kg. The subcutaneous LD50 in mice is 2.1 g/kg.
Sudden loss of consciousness, simultaneous respiratory and metabolic acidosis, fast heartbeat, increased blood pressure, pupil constriction, coma, respiratory depression and death may follow from an overdose. Somebody who has overdosed and suffers from respiratory depression may be kept alive by performing a tracheal intubation and then giving artificial respiration with pumps.

Metabolism

In rats, TAA is primarily metabolized via glucuronidation, as well as by oxidation to 2-methyl-2,3-butanediol. It is likely that the same path is followed in humans, though older sources suggest TAA is excreted unchanged.
The use of TAA cannot be detected with general ethanol tests or other ordinary drug tests. Its use can be detected from a blood or a urine sample by using gas chromatography–mass spectrometry for up to 48 hours after consumption.