Isophorone

Structural formula
General
Surname	Isophorone
other names	3,5,5-trimethyl-2-cyclohexen-1-one 3,5,5-trimethylcyclohex-2-enone
Molecular formula	C 9 H 14 O
Brief description	colorless liquid with a peppermint odor
External identifiers / databases
CAS number 78-59-1 EC number 201-126-0 ECHA InfoCard 100.001.024 PubChem 6544 Wikidata Q415519
properties
Molar mass	138.21 g mol −1
Physical state	liquid
density	0.92 g cm −3 (20 ° C)
Melting point	−8.1 ° C , -8 ° C
boiling point	215 ° C, 215.5 ° C
Vapor pressure	33 Pascal (20 ° C)
solubility	poor in water (14.5 g l −1 at 20 ° C)
Refractive index	1.4766 (18 ° C), 1.4775
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary Caution H and P phrases H: 302-312-319-335-351 P: 261-280-305 + 351 + 338
MAK	DFG / Switzerland: 2 ml m −3 or 11 mg m −3
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Isophorone is a chemical compound from the group of cyclic enones and a derivative of 2-cyclohexen-1-one .

history

Isophorone was first marketed as a possible acetone product in 1967 by what was then Hibernia Chemie (now Evonik Industries ); its sale secured their location in Herne .

Occurrence

Cranberries

Isophorone is also said to occur naturally in cranberries . Although direct contact with isophorone causes irritation, there is no convincing evidence for the toxicity of the substance with long-term use.

Extraction

Isophorone can be produced by catalyzed autocondensation of acetone .

In 2003 the annual production capacity for isophorone was 50,000 t / a.

properties

Isophorone is a colorless to yellowish liquid with a characteristic odor (like camphor). It is miscible with aromatic and aliphatic hydrocarbons , aldehydes , ketones , alcohols , esters and ethers . The flash point is 95 ° C , the ignition temperature at 470 ° C .

There are two constitutional isomers that are grouped under the name isophorone, namely alpha-isophorone and beta-isophorone . The former carries the C = C double bond between carbon atoms 2 and 3, so it is an alpha-beta-unsaturated carbonyl ; the latter carries the double bond between carbon atoms 3 and 4. Isophorone usually contains 1–3% of the beta isomer.

use

Isophorone is used as a solvent in the varnish, paint and adhesive industries.

In synthesis, it is mainly used as an intermediate for the production of isophoronediamine , isophorone diisocyanate and 3,5-dimethylphenol or 2,3,5-trimethylphenol.

Isophoron is a component of colored indicators with positive solvatochromism (LSG Brooker and Ralf E. Lemke) and the negative solvatochromic anions with positive thermochromism (Ralf E. Lemke).

Furthermore, isophorone can be hydrogenated to 3,3,5-trimethylcyclohexanone or 3,3,5-trimethylcyclohexanol, which can be oxidized to trimethyladipic acid.

Risk assessment

In 2012, isophorone was included in the EU's ongoing action plan ( CoRAP ) in accordance with Regulation (EC) No. 1907/2006 (REACH) as part of substance evaluation . The effects of the substance on human health and the environment are re-evaluated and, if necessary, follow-up measures are initiated. Isophorone uptake was caused by concerns about its classification as a CMR substance, worker exposure , high (aggregated) tonnage and widespread use. The re-evaluation took place from 2013 and was carried out by France .

Individual evidence

1. ↑ ^{a b c d e f g h i} Entry on 3,5,5-trimethylcyclohex-2-enone in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .
2. ↑ ^{a b c d e f} M. Bohnet, CJ Brinker, B. Cornils, TJ Evans, H. Greim, LL Hegedus, J. Heitbaum, WA Herrmann, W. Keim, A. Kleemann, G. Kreysa, T. Laird , J. Löliger, RO McClellan, JL McGuire, JW Mitchell, A. Mitsutani, T. Onoda, L. Plass, G. Stephanopoulos, D. Werner, P. Woditsch, N. Yoda: Ullmanns Encyclopedia of industrial chemistry . 6th edition. 18 "Information Storage to Ketones". Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 2003, ISBN 3-527-30385-5 , pp. 745, f .
3. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-312.
4. ↑ Entry on 3,5,5-trimethylcyclohex-2-enone in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
5. ↑ Swiss Accident Insurance Fund (Suva): Limit values ​​- current MAK and BAT values (search for 78-59-1 or isophorone ), accessed on November 2, 2015.
6. ↑ Isophorone. So that the paint is not off. Article from Evonik Industries, accessed on October 28, 2015.
7. ↑ Chronic Toxicity Summary ( Memento of the original from September 22, 2006 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 36 kB).  
8. ↑ US Patent 5849957 .
9. ↑ Community rolling action plan ( CoRAP ) of the European Chemicals Agency (ECHA): 3,5,5-trimethylcyclohex-2-enone , accessed on March 26, 2019.