1,4-Butanediol

1,4-Butanediol
IUPAC name Butane-1,4-diol
Other names Tetramethylene glycol
Identifiers
CAS number	110-63-4 Y
ChemSpider	7773
EC-number	203-786-5
RTECS number	EK0525000
SMILES OCCCCO
InChI InChI=1/C4H10O2/c5-3-1-2-4-6/h5-6H,1-4H2
Properties[1][2]
Molecular formula	C4H10O2
Molar mass	90.121 g/mol
Density	1.0171 g/cm3 (20 °C)
Melting point	20.1 °C
Boiling point	235 °C
Solubility in water	miscible
Solubility in ethanol	soluble
Refractive index (nD)	1.4460 (20 °C)
Hazards[2][3]
EU Index	not listed
GHS pictograms
GHS signal word	WARNING
GHS hazard statements	H302
GHS precautionary statements	P264, P270, P301+312, P330, P501
NFPA 704	1 1 0
Flash point	121 °C (open cup)
Autoignition temperature	350 °C
Related compounds
Related butanediols	1,2-Butanediol 1,3-Butanediol 2,3-Butanediol
Related compounds	Succinaldehyde Succinic acid
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

1,4-Butanediol is the organic compound with the formula HOCH₂CH₂CH₂CH₂OH. This colorless viscous liquid is derived from butane by placement of alcohol groups at each end of the chain. It is one of four stable isomers of butanediol.

Synthesis

In its industrial synthesis, acetylene reacts with two equivalents of formaldehyde to form 1,4-butynediol, also known as but-2-yne-1,4-diol. 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.

LyondellBasell manufactures 1,4-butanediol in a proprietary, multi-step process without the use of acetylene. First, propylene oxide is converted to allyl alcohol. The allyl alcohol is then hydroformylated to 4-hydroxybutyraldehyde. Hydrogenation of the 4-hydroxybutyraldehyde yields 1,4-butanediol.^[4]

It can also be manufactured on an industrial scale by the vapour phase hydrogenation of the esters and anhydrides of maleic acid and succinic acid.

Genomatica (a San Diego-based company) has genetically engineered E. coli to metabolize sugar into 1,4-butanediol. They expect to build and begin operating a pilot plant by the end of 2009. Genomatica CEO Christopher Gann said the process consumes 32,000 BTU per pound of 1,4-butanediol (75 MJ/kg), far less than the acetylene-based process, and does not have any by-products.^[5][6]

Industrial use

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.^[7] At about 200 °C in the presence of soluble ruthenium catalysts, the diol undergoes dehydrogenation to form butyrolactone.^[8]

World production of 1,4-butanediol is about one million metric tons per year and market price is about 2,000 USD (1,600 EUR) per ton (2005). Almost half of it is dehydrated to tetrahydrofuran to make fibers such as Spandex.^[9] The largest producer is BASF.^[10]

Health effects and use as a drug

FDA warning against products containing GHB and its prodrugs, such as 1,4-Butanediol.

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.^[11][12]

Anecdotal reports indicate that 1,4-butanediol produces a strong toxic feeling not present with GHB when ingested.^[13] These reports also indicate that it may cause damage to the liver as well as to other vital organs.^[14] Abuse has also resulted in addiction and death.^[15][16][17]

Pharmacokinetics

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.^[18] Because these enzymes are also responsible for metabolizing alcohol there is a strong chance of a dangerous drug interaction.^[18][19] 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-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.^[18]

Pharmacodynamics

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 some evidence that 1,4-butanediol may have inherent alcohol-like pharmacological effects that are not due to this conversion.^[19]

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. Additionally, individuals have been prosecuted for 1,4-butanediol under the Federal Analog Act as substantially similar to GHB. Scheduling of 1,4-butanediol on a federal level seems unlikely considering its legitimate industrial applications.

2007 contamination of Bindeez toy

A toy called "Bindeez" ("Aqua Dots" in North America) was recalled by the distributor in November 2007 because of the presence of 1,4-butanediol. The toy consists of small beads that stick to each other by sprinkling water. 1,4-Butanediol was detected by GC-MS.^[20] The production plant seems to have intended to cut costs by replacing less toxic 1,5-pentanediol with 1,4-butanediol. ChemNet China listed the price of 1,4 butanediol at between about US$1,350–2,800 per metric ton, while the price for 1,5-pentanediol is about US$9,700 per metric ton.^[21]

References

External links

• International Chemical Safety Card 1104
• SIDS Initial Assessment Report for 1,4-Butanediol from the Organisation for Economic Co-operation and Development (OECD)
• NLM Hazardous Substances Data Bank entry for 1,4-Butanediol