2-methyl-1-propanol

Structural formula
General
Surname	2-methyl-1-propanol
other names	i -butanol; iso- butanol; Isobutanol; Isobutyl alcohol; 2-methylpropan-1-ol; 2-methylpropanol; 2-METHYL PROPANOL ( INCI ) ;
Molecular formula	C 4 H 10 O
Brief description	colorless liquid with a fusel oil odor
External identifiers / databases
EC number	201-148-0
ECHA InfoCard	100.001.044
PubChem	6560
Wikidata	Q151797
properties
Molar mass	74.12 g mol −1
Physical state	liquid
density	0.80 g cm −3
Melting point	−108 ° C
boiling point	108 ° C
Vapor pressure	11.8 h Pa (20 ° C); 22.8 hPa (30 ° C); 41.8 hPa (40 ° C); 73.8 hPa (50 ° C);
solubility	moderate in water (85 g l −1 at 20 ° C); miscible with ethanol, diethyl ether and acetone;
Refractive index	1.3955 (20 ° C)
safety instructions
H and P phrases	H: 226-335-315-318-336
	P: 210-280-302 + 352-305 + 351 + 338
MAK	DFG : 100 ml m −3 or 310 mg m −3 ; Switzerland: 50 ml m −3 or 150 mg m −3 ;
Toxicological data	2460 mg kg −1 ( LD 50 , rat , oral ) ; 3400 mg kg −1 ( LD 50 , rabbit , transdermal ) ;
	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

2-Methyl-1-propanol (also i- butanol or isobutanol) belongs to the group of alkanols , which in turn belong to the alcohols . Isobutanol comes e.g. B. in fusel oil .

Extraction and presentation

Isobutanol and 1-butanol are obtained chemically by hydroformylation or hydrocarbonylation of propene . In contrast to the production of 1-butanol, you continue to work with the other reaction product and hydrogenate it:

Propene reacts with carbon monoxide and hydrogen to form butanal and 2-methylpropanal .

The resulting 2-methylpropanal reacts with hydrogen to form 2-methyl-1-propanol.

Isobutanol can be produced biotechnologically with the help of microorganisms . Then it serves as a regenerative biofuel, similar to 1-butanol .

properties

Physical Properties

2-methyl-1-propanol is a colorless liquid that smells sweet. Like all butanols, 2-methyl-1-propanol is also flammable. Can be 2-methyl-1-propanol with all common organic solvents such as ether , ethylene glycol , alcohols , ketones and aldehydes mix as desired, in water , however, it is only sparingly soluble.

The compound forms azeotropically boiling mixtures with a number of other solvents . The azeotropic compositions and boiling points can be found in the following table. No azeotropes are formed with methanol , ethanol , n-propanol , 2-propanol , n-butanol , 2-butanol , ethanediol , chloroform , acetone , dibutyl ether , ethyl acetate , isopropyl acetate , n-butyl acetate , DMSO , acetonitrile and carbon disulfide .

Azeotropes with various solvents
solvent		water	n-hexane	n-heptane	Cyclohexane	Dioxane
Content of 2-methyl-1-propanol	in %	67	2	27	14th	4th
boiling point	in ° C	89	68	91	78	101

solvent		benzene	toluene	Ethylbenzene	Xylene	Methyl isobutyl ketone
Content of 2-methyl-1-propanol	in %	8th	45	80	88	91
boiling point	in ° C	79	101	107	107	108

Chemical properties

Reactions

Possible reactions of 2-methyl-1-propanol are esterification to an ester , dehydrogenation to an aldehyde , oxidation to a carboxylic acid and the elimination of water to form an alkene .

2-Methyl-1-propanol reacts with acetic acid to form isobutyl acetate and water.

Dehydration of 2-methyl-1-propanol to 2-methylpropanal .

2-methyl-1-propanol is oxidized to 2-methylpropanoic acid.

2-Methyl-1-propanol reacts to 2-methylpropene with elimination of water .

Safety-related parameters

2-methyl-1-propanol forms highly flammable vapor-air mixtures. The compound has a flash point of 27 ° C. The explosion range is between 1.7% by volume (52 g / m ³ ) as the lower explosion limit (LEL) and 11% by volume (340 g / m ³ ) as the upper explosion limit (UEL). Correlating the explosion limits with the vapor pressure function results in a lower explosion point of 26 ° C and an upper explosion point of 59 ° C. The maximum explosion pressure is 8.5 bar. The limit gap width was determined to be 0.94 mm (50 ° C). This results in an assignment to explosion group IIA. The ignition temperature is 430 ° C. The substance therefore falls into temperature class T2.

use

2-Methyl-1-propanol is used in derivatives as a solvent for the synthesis of plasticizers and esters , which are used as fragrances and aromas, but also as solvents, thinners and additives in nitrocellulose lacquers, synthetic resins, cleaning agents, printing inks and in fuel. It is mainly used in the paint industry and improves the properties of paints. It is also being used as a fuel in long-distance motorsport tests.

Individual evidence

↑ Entry on 2-METHYLPROPANOL in the CosIng database of the EU Commission, accessed on February 25, 2020.
↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r ^s ^t Entry on 2-methyl-1-propanol in the GESTIS substance database of the IFA , accessed on December 27, 2019(JavaScript required) .
↑ ^a ^b ^c ^d Toxicological assessment of 2-methylpropanol-1 (PDF) at the professional association raw materials and chemical industry (BG RCI), accessed on May 1, 2018.
↑ 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. 3-370.
↑ Entry on 2-methylpropan-1-ol 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 .
↑ Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 78-83-1 or 2-methyl-1-propanol ), accessed on November 2, 2015.
↑ Alexandra M. Goho: Bacteria produce butanol ; Technology Review ; January 30, 2008.
↑ ^a ^b I. M. Smallwood: Handbook of organic solvent properties. Arnold, London 1996, ISBN 0-340-64578-4 , pp. 12-13.
↑ ^a ^b ^c ^d ^e E. Brandes, W. Möller: Safety-related parameters. Volume 1: Flammable Liquids and Gases. Wirtschaftsverlag NW - Verlag für neue Wissenschaft, Bremerhaven 2003.
↑ ^a ^b D. Stoye: Solvents. In: Ullmann's Encyclopedia of Technical Chemistry . Wiley-VCH Verlag, Weinheim 2012, doi : 10.1002 / 14356007.a24_437 .

[CosIng-1] Entry on 2-METHYLPROPANOL in the CosIng database of the EU Commission, accessed on February 25, 2020.

[GESTIS-2] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r ^s ^t Entry on 2-methyl-1-propanol in the GESTIS substance database of the IFA , accessed on December 27, 2019(JavaScript required) .

[bgc-3] Toxicological assessment of 2-methylpropanol-1 (PDF) at the professional association raw materials and chemical industry (BG RCI), accessed on May 1, 2018.

[CRC90_3_370-4] 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. 3-370.

[CLP_100.001.044-5] Entry on 2-methylpropan-1-ol 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 .

[6] Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 78-83-1 or 2-methyl-1-propanol ), accessed on November 2, 2015.

[7] Alexandra M. Goho: Bacteria produce butanol ; Technology Review ; January 30, 2008.

[Smallwood-8] I. M. Smallwood: Handbook of organic solvent properties. Arnold, London 1996, ISBN 0-340-64578-4 , pp. 12-13.

[Brandes-9] E. Brandes, W. Möller: Safety-related parameters. Volume 1: Flammable Liquids and Gases. Wirtschaftsverlag NW - Verlag für neue Wissenschaft, Bremerhaven 2003.

[Ullmann-10] D. Stoye: Solvents. In: Ullmann's Encyclopedia of Technical Chemistry . Wiley-VCH Verlag, Weinheim 2012, doi : 10.1002 / 14356007.a24_437 .