2,2-dimethoxypropane

Structural formula
General
Surname	2,2-dimethoxypropane
other names	Acetone dimethyl acetal
Molecular formula	C 5 H 12 O 2
Brief description	colorless liquid with an aromatic odor
External identifiers / databases
CAS number 77-76-9 EC number 201-056-0 ECHA InfoCard 100,000,961 PubChem 6495 Wikidata Q4596749
properties
Molar mass	104.15 g mol −1
Physical state	liquid
density	0.85 g cm −3
Melting point	−47 ° C
boiling point	83 ° C
Vapor pressure	80 hPa (15.8 ° C)
solubility	Easily soluble in water (180 g l −1 at 20 ° C)
Refractive index	1.378 (20 ° C)
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 225-319 P: 210-305 + 351 + 338
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

2,2-Dimethoxypropane is a chemical compound from the group of acetals .

Extraction and presentation

2,2-Dimethoxypropane can be obtained by reacting acetone and methanol .

properties

2,2-Dimethoxypropane is a highly flammable, volatile, colorless liquid with an aromatic odor that is easily soluble in water.

use

2,2-Dimethoxypropane is an organic building block that is often used as a precursor for the production of 2-methoxypropene . It also serves as an intermediate in the synthesis of vitamin E , vitamin A and various carotenoids such as astaxanthin . It is used as a reagent for the preparation of 1,2- diols , acetonides , isopropylidene derivatives of sugars, nucleosides, methyl esters of amino acids and enol ethers. Since the compound decomposes again into methanol and acetone on contact with water, this can be used for the determination of water in natural products.

The acid- catalyzed hydrolysis of 2,2-dimethoxypropane to acetone and methanol is also used in process engineering to characterize the mixing quality of equipment such as B. stirred tanks and static mixers with continuous flow . For this purpose, an acidic aqueous solution (usually with dilute hydrochloric acid ) is brought into contact with an alkaline aqueous solution (usually with sodium hydroxide solution ) of 2,2-dimethoxypropane, the alkali being slightly in excess. Since the neutralization takes place faster than the hydrolysis, almost no acetone and methanol would be produced with ideal mixing, since the protons present are consumed by the neutralization reaction. The conversion of the hydrolysis thus serves as an indicator of the mixing quality.

safety instructions

The vapors of 2,2-dimethoxypropane can form an explosive mixture with air ( flash point −11 ° C).

Individual evidence

1. ↑ ^{a b c d e f g h i j k} Entry on 2,2-dimethoxypropane in the GESTIS substance database of the IFA , accessed on November 4, 2018(JavaScript required) .
2. ↑ ^{a b} data sheet 2,2-dimethoxypropane, reagent grade, 98% from Sigma-Aldrich , accessed on November 4, 2018 ( PDF ).
3. ^ Sun Refining and Marketing Company: Process for the production of 2,2-dimethoxypropane - Sun Refining and Marketing Company , accessed November 4, 2018
4. ↑ Data sheet 2,2-Dimethoxypropane, 98% from AlfaAesar, accessed on November 4, 2018 ( PDF )(JavaScript required) .
5. ^ Nouri Y. Mary: Gas chromatographic determination of water in natural products by reaction with 2,2-dimethoxypropane. In: Journal of Pharmaceutical Sciences. 58, 1969, p. 1089, doi : 10.1002 / jps.2600580910 .
6. ↑ Andreas Kölbl, Manfred Kraut: Characterization of a temperable mixer with the Acetal Cleavage Method. In: Chemical Engineering Journal. 227, 2013, doi : 10.1016 / j.cej.2012.11.124 .
7. ↑ Craig P. Holvey et al .: Pressure drop and mixing in single phase microreactors: Simplified designs of micromixers. In: Chemical Engineering and Processing: Process Intensification. 50 (10), 2011, doi : 10.1016 / j.cep.2011.05.016 .