Isoprenol
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Names | |
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Preferred IUPAC name 3-Methylbut-3-en-1-ol | |
Other names 3-Methyl-3-buten-1-ol | |
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ECHA InfoCard | 100.011.009 ![]() |
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Properties[1] | |
Chemical formula | C5H10O |
Molar mass | 86.132 g/mol |
Density | 0.853 g/cm3 |
Boiling point | 130 to 132 °C (266 to 270 °F; 403 to 405 K) |
Refractive index (nD) | 1.433 |
Hazards[2] | |
GHS labelling: | |
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Warning | |
Hazard statements | H226, H319 |
Precautionary statements | P210, P233, P240, P241, P242, P243, P264, P280, P303+P361+P353, P305+P351+P338, P337+P313, P370+P378, P403+P235, P501 |
Flash point | 36 °C (97 °F; 309 K)[note 1] |
Related compounds | |
Related compounds | Prenol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). ![]() ![]() ![]() Infobox references |
Chemical compound
Isoprenol, also known as 3-methylbut-3-en-1-ol, is a hemiterpene alcohol. It is produced industrially as an intermediate to 3-methylbut-2-en-1-ol (prenol): global production in 2001 can be estimated as 6–13 thousand tons.[3]
Isoprenol is produced by the reaction between isobutene (2-methylpropene) and formaldehyde.
![The reaction of isobutene with formaldehyde to give isoprenol, the first step in the industrial manufacture of prenol.](http://upload.wikimedia.org/wikipedia/commons/thumb/a/ad/Isoprenol_prepn.png/435px-Isoprenol_prepn.png)
The thermodynamically preferred prenol with the more substituted double bond cannot be directly formed in the above reaction, but is produced via a subsequent isomerisation:
![The isomerization of isoprenol to prenol, the second step in the industrial manufacture of prenol.](http://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/Prenol_prepn.png/383px-Prenol_prepn.png)
This isomerisation reaction is catalyzed by any species which can form an allyl complex without excessive hydrogenation of the substrate, for example poisoned palladium catalysts.[4]
Notes
- ^ Sigma-Aldrich Co. gives a value for the flash point of isoprenol of 42 °C (108 °F). The difference in the two values does not alter the safety classification of isoprenol as a category 3 flammable liquid under the GHS; but the lower value quoted here (from the New Zealand Environmental Risk Management Authority) would make it a class IC flammable liquid instead of a class II combustible liquid under the U.S. OSHA classification (29 C.F.R § 1910.106), and F3 rather than F2 under the NFPA 704 standard.
References
- ^ Sigma-Aldrich Co., 3-Methyl-3-buten-1-ol. Retrieved on 2009-08-31..
- ^ HSNO Chemical Classification Information Database, New Zealand Environmental Risk Management Authority, retrieved 2009-08-31.
- ^ 3-Methyl-2-buten-1-ol (PDF), SIDS Initial Assessment Report, Geneva: United Nations Environment Programme, May 2005. Major produce in a world is BASF(Germany) and Kuraray(Japan).
- ^ See, e.g., Kogan, S. B.; Kaliya, M.; Froumin, N. (2006), "Liquid phase isomerization of isoprenol into prenol in hydrogen environment", Appl. Catal. A: Gen., 297 (2): 231–36, doi:10.1016/j.apcata.2005.09.010.