2-methylvaleraldehyde

Structural formula
	Simplified structural formula without stereochemistry
General
Surname	2-methylvaleraldehyde
other names	2-methylpentanal ( IUPAC ); alpha-methylpentanal; (±) -2-methylpentanal; 2-methylpentaldehyde; 2-formylpentane;
Molecular formula	C 6 H 12 O
Brief description	colorless to yellowish liquid with a pungent odor
External identifiers / databases
EC number	204-605-2
ECHA InfoCard	100.004.188
PubChem	31245
ChemSpider	28985
Wikidata	Q27162196
properties
Molar mass	100.16 g mol −1
Physical state	liquid
density	0.81 g cm −3 (20 ° C)
Melting point	−100 ° C
boiling point	118 ° C
Vapor pressure	19.3 h Pa (20 ° C); 25.5 hPa (25 ° C); 88.4 hPa (50 ° C);
solubility	hardly soluble in water (4.2 g l −1 )
Refractive index	1,400 (20 ° C)
safety instructions
H and P phrases	H: 225-315-319-335
	P: 210-302 + 352-305 + 351 + 338
Toxicological data	> 3200 mg kg −1 ( LD 50 , rat , oral )
	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-methylvaleraldehyde is an organic-chemical compound from the group of aldehydes . It is used as an intermediate product in the manufacture of more highly refined products such as agrochemicals , fragrances and dyes as well as catalysts for polymer synthesis (especially polyester ) in the chemical industry .

Isomerism

2-Methylvaleraldehyde occurs in two stereoisomeric forms because it has a stereocenter on the C2 atom . Hence the two enantiomers (R) -2-methylvaleraldehyde and (S) -2-methylvaleraldehyde exist. Without any further specifying addition, what is usually meant is a mixture of the two substances, which is referred to as a racemate .

Extraction and presentation

One possibility for the industrial production of racemic 2-methylvaleraldehyde consists in the aldol condensation of propionaldehyde in the presence of basic catalysts and subsequent selective catalytic hydrogenation of the 2-methyl-2-pentenal formed.

Further, it is also by gentle oxidation of 2-methyl pentanol accessible.

properties

Physical Properties

2-Methylvaleraldehyde has a relative gas density of 3.45 (density ratio to dry air at the same temperature and pressure ) and a relative density of the steam-air mixture of 1.03 (density ratio to dry air at 20 ° C and normal pressure ). In addition, 2-methylpentanal has a dynamic viscosity of 0.61 mPa · s at a temperature of 20 ° C.

Chemical properties

2-Methylvaleraldehyde is a highly flammable liquid from the group of aldehydes . It is sparingly soluble in water and lighter than water. 2-methylpentanal is of medium or low volatility. Aqueous solutions of 2-methylpentanal are acidic. A solution with 4.2 g / l has a pH value of 4 at 20 ° C.

use

2-Methylvaleraldehyde is not used very well in the chemical industry. The compound is mainly used as an intermediate in the manufacture of other chemical products. These include in particular agrochemicals , fragrances , fragrances and dyes as well as catalyst systems for the synthesis of plastics . Furthermore, 2-methylpentanal is an important precursor used in the manufacture of sedatives such as meprobamate and mebutamate .

safety instructions

The vapors of 2-methylvaleraldehyde can form explosive mixtures with air. 2-Methylpentanal is mainly absorbed through the respiratory tract , absorption through the skin and the digestive tract is strongly suspected. Ingestion or ingestion can cause irritation to the eyes , respiratory tract and skin . To date, there is insufficient information on reproductive toxicity and carcinogenicity . For structurally similar aldehydes, however, a certain mutagenic effect was found by in vitro tests, but not evaluated. 2-Methylvaleraldehyde has a lower explosion limit (LEL) of 1.6% by volume and an upper explosion limit (UEL) of 6.6% by volume. The ignition temperature is 195 ° C. The substance therefore falls into temperature class T4. With a flash point of 16 ° C, 2-methylpentanal is considered highly flammable.

Web links

Commons : 2-Methylvaleraldehyde - Collection of pictures, videos, and audio files

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ Entry on 2-methylvaleraldehyde in the GESTIS substance database of the IFA , accessed on January 8, 2020(JavaScript required) .
↑ ^a ^b ^c , he was appointed, Markus Schulte, Jürgen Falbe, Peter Lappe, Juergen Weber, Guido D. Frey: aldehyde, Aliphatic. In: Ullmann's Encyclopedia of Industrial Chemistry . Wiley ‐ VCH Verlag GmbH & Co. KGaA., January 15, 2013, doi : 10.1002 / 14356007.a01_321.pub3 .
↑ Entry on 2-methylvaleraldehyde in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on December 4, 2019. Manufacturers or distributors can expand the harmonized classification and labeling .

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ Entry on 2-methylvaleraldehyde in the GESTIS substance database of the IFA , accessed on January 8, 2020(JavaScript required) .

[ULLMANN-2] , he was appointed, Markus Schulte, Jürgen Falbe, Peter Lappe, Juergen Weber, Guido D. Frey: aldehyde, Aliphatic. In: Ullmann's Encyclopedia of Industrial Chemistry . Wiley ‐ VCH Verlag GmbH & Co. KGaA., January 15, 2013, doi : 10.1002 / 14356007.a01_321.pub3 .

[CLP_100.004.188-3] Entry on 2-methylvaleraldehyde in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on December 4, 2019. Manufacturers or distributors can expand the harmonized classification and labeling .