1,4-Butynediol

• But-2- yne-1 ,4 -diol
• 1,4- butyne diol
• Bis (hydroxymethyl ) acetylene
• Butindiol

Colorless solid

Fixed

1.04 to 1.05 g · cm -3

58 ° C

238 ° C

<10 Pa ( 20 ° C)

• Very slightly soluble in water: 3740 g · l-1 (25 ° C)
• Slightly soluble in ethanol and acetone

Risk

0.2 mg · m-3

~ 100 mg · kg -1 ( LD50, rat, oral)

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2-butyne- 1 ,4-diol is an organic chemical compound is selected from the group consisting of alkynes, and a diol (that is, an alkynol ). The colorless to yellow crystalline solid is highly soluble in water and slightly soluble in ethanol.

Production and representation

Butindiol can be obtained by Reppe synthesis, ethyne and an aqueous solution of formaldehyde under pressure to react with each other ( a large plant was built in 1941 ):

The reaction proceeds normally at a temperature in the range of 90 to 150 ° C, dependent on the pressure ( 1-20 bar). Various patented methods for producing butynediol using copper-bismuth layers on an inert carrier material, or copper acetylide catalyst.

The European annual production of 200,000 t Butindiol is about a year.

Use

Butindiol is the starting point for the synthesis of other diols. It can be reacted by hydrogenation to 1,4- butenediol and further to 1,4-butanediol. Furthermore, it is for the preparation of drugs, such as as a raw material for vitamin B6, defoliants, flame retardants, corrosion inhibitors, plasticizers and polyurethane ( chain extending agent). It also serves as a brightener in electroplating baths ( nickel and copper ) and as pickling inhibitors addition to the removal of scale or oxide coatings on metals and in pickling colors

Safety

2 -butyne -1 ,4 -diol decomposes easily in the heat ( above 160 ° C), which may precipitate the reaction in the presence of impurities or at higher temperatures very violent (flash point 136 ° C).