1,4-Butanediol

1,4-Butanediol, colloquially known as BD, is the organic compound with the formula HOCH2CH2CH2CH2OH. It is a colorless viscous liquid. It is one of four stable isomers of butanediol. 1,4-Butanediol, colloquially known as BD, is the organic compound with the formula HOCH2CH2CH2CH2OH. It is a colorless viscous liquid. It is one of four stable isomers of butanediol. In its industrial synthesis, acetylene reacts with two equivalents of formaldehyde to form 1,4-butynediol. This type of acetylene-based process is illustrative of what is known as 'Reppe chemistry', after German chemist Walter Reppe. Hydrogenation of 1,4-butynediol gives 1,4-butanediol. This route is used by BASF and Ashland/ISP. It is also manufactured on an industrial scale from maleic anhydride in the Davy process, which is first converted to the methyl maleate ester, then hydrogenated. Other routes are from butadiene, allyl acetate and succinic acid. A biological route to BDO has been commercialized that uses a genetically modified organism. The biosynthesis proceeds via 4-hydroxybutyrate. 1,4-Butanediol is used industrially as a solvent and in the manufacture of some types of plastics, elastic fibers and polyurethanes. 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 soluble ruthenium catalysts, the diol undergoes dehydrogenation to form butyrolactone. World production of 1,4-butanediol was claimed to be about one million metric tons per year and market price is about US$2,000 (€1,600) per ton (2005). In 2013, worldwide production was claimed to be billions of lbs (consistent with approximately one million metric tons). Almost half of it is dehydrated to tetrahydrofuran to make fibers such as Spandex. The largest producer is BASF. 1,4-Butanediol is also used as a recreational drug known by some users as 'One Comma Four', 'Liquid Fantasy', '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. When mixed with other drugs, misuse of 1,4-butanediol has resulted in addiction and death. 1,4-Butanediol 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. While co-administration of ethanol and GHB already poses serious risks, co-administration of ethanol with 1,4-butanediol will interact considerably and has many other potential risks. This is because the same enzymes that are responsible for metabolizing alcohol also metabolize 1,4-butanediol so there is a strong chance of a dangerous drug interaction. Emergency room patients who overdose on both ethanol and 1,4-butanediol often present with symptoms of alcohol intoxication initially and as the ethanol is metabolized the 1,4-butanediol 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. 1,4-Butanediol seems to have two types of pharmacological actions. The major psychoactive effects of 1,4-butanediol are because it is metabolized into GHB; however there is a study suggesting that 1,4-butanediol may have potential alcohol-like pharmacological effects that are not due to this conversion. The study arrived at this conclusion based on the finding that 1,4-butanediol co-administered with ethanol led to potentiation of some of the behavioral effects of ethanol. However, potentiation of ethanol's effects may simply be caused by competition for the alcohol dehydrogenase and aldehyde dehydrogenase enzymes with co-administered 1,4-butanediol. The shared metabolic rate-limiting steps thus leads to slowed metabolism and clearance for both compounds including ethanol's known toxic metabolite acetaldehyde.