1,4-Butanediol

1,4-Butanediol is an alcohol derivative of the alkane butane, carrying two hydroxyl groups. It is a colorless viscous liquid.

Synthesis
Its industrial synthesis starts with acetylene, which is reacted with two molecules of formaldehyde to form 1,4-butynediol, also known as but-2-yne-1,4-diol, a process known as the Reppe synthesis. This product is subsequently hydrogenated to give 1,4-butanediol.

It is also manufactured on an industrial scale by the vapour phase hydrogenation of maleate esters.

Uses
1,4-Butanediol is used industrially as a solvent and in the manufacture of some types of plastics and fibers. In organic chemistry, 1,4-butanediol is used for the synthesis of γ-butyrolactone (GBL). In the presence of phosphoric acid and high temperature, it dehydrates to the important solvent tetrahydrofuran. . At about 200 °C in the presence of a soluble ruthenium catalyst, the diol loses H2 and forms butyrolactone.

It is also used as a recreational drug known by some users as "One Comma Four", "One Four Bee" or "One Four B-D-O". It exerts effects similar to γ-hydroxybutyrate (GHB), which is a metabolic product of 1,4-butanediol.

Anecdotal reports indicate that 1,4-butanediol produces a strong toxic feeling not present with GHB when ingested. These reports also indicate that it may cause damage to the liver as well as to other vital organs. Abuse has also resulted in addiction and death.

Pharmacokinetics
1,4-Butandiol is converted into GHB by the enzymes alcohol dehydrogenase and aldehyde dehydrogenase and differing levels of these enzymes may account for differences in effects and side effects between users. Because these enzymes are also responsible for metabolizing alcohol there is a strong chance of a dangerous drug interaction. Emergency room patients who overdose on both alcohol and 1,4-butanediol often present with symptoms of ethanol intoxication initially and as the ethanol is metabolized the 1,4-butandiol is then able to better compete for the enzyme and a second period of intoxication ensues as the 1,4-butanediol is converted into GHB.

Pharmacodynamics
1,4-Butanediol seems to have two types of pharmacological actions. The major psychoactive effects of 1,4-butanediol are due to the fact that it is metabolized into GHB, however there is some evidence that 1,4-butanediol may have inherent alcohol-like pharmacological effects that are not due to this conversion.

Legality
While 1,4-butanediol is not currently scheduled federally in the United States, a number of states have classified 1,4-butanediol as a controlled substance and even where it has not yet been scheduled. Scheduling of 1,4-butanediol on a federal level is highly unlikely considering its common industrial use and many industrial applications.