How to convert methylamine to acetone



acetone is the common name for Propanone or Dimethyl ketone, the simplest ketone. Acetone is a colorless liquid and is used as an aprotic solvent and as a starting material for syntheses in organic chemistry. Its characteristic structural feature is the carbonyl group, which is linked with two methyl groups.

properties

Acetone is a colorless, low-viscosity liquid with a characteristic (fruity / sweet) odor, pungent in higher concentrations, highly flammable and forms an explosive mixture with air. It is miscible in all proportions with water and most organic solvents. The acetone molecule shows keto-enol tautomerism; its pKa value is 20.

Manufacturing

The most important manufacturing process for acetone is the cumene hydroperoxide process, which is also known as the Hock phenol synthesis:

Here benzene and propene are first converted into isopropylbenzene (cumene) by a Friedel-Crafts alkylation in an acid, hence the name of the reaction. Cumene is then oxidized with oxygen, producing a hydroperoxide. This decomposes to phenol and acetone during the acidic work-up.

The dehydrogenation or oxydehydrogenation of isopropanol is carried out as a further production process.

Another way of producing acetone is to heat calcium acetate, which breaks it down into acetone and calcium oxide. (Known as "lime salt distillation")

Reactions

The iodination of acetone as a classic example of pseudo-zero order reaction kinetics should be mentioned here as a special reaction. Since iodine can only be added to the enol form, but acetone is almost 100% ketone, the 2-propenol concentration during the reaction can be viewed as constant:

H3C H3C | | C = O ⇌ C-O-H | ǁ H3C H2C.

As with the determination of the iodine number, iodine can now be added to the C = C double bond:

H3C H3C | | C-O-H + I2 → I-C-O-H ǁ | H2C H2C-I

In the last step, the ketone is restored by folding the C-I bond to the iodine and at the same time folding the O-H bond to the C = O double bond. The iodide reacts with the released proton to form hydrogen iodide:

H3C H3C | | I-C-O-H → C = O + HI | | H2C-I H2C-I

The entire reaction is acid catalyzed. If base is added, however, the iodoform reaction takes place.

use

Acetone is used as a common solvent and extraction agent for resins, fats and oils, rosin, cellulose acetate and as a nail polish remover. It dissolves many times its volume in ethyne (acetylene). Acetone is used in many reactions (aldol additions and aldol condensations) in organic chemistry and is often a standard molecule in teaching for examples of carbonyl chemistry.

If two acetone molecules are allowed to dimerize in an aldol-like manner under the influence of basic reagents, diacetone alcohol is formed.

Acetone, together with hydrogen peroxide, is one of the basic chemicals used in the manufacture of the explosive acetone peroxide.

In some countries acetone is added in small proportions (1: 2000-1: 5000) to gasoline or diesel in order to achieve a more complete combustion of the fuel.

biochemistry

Acetone is a ketone body that cannot be metabolized to any significant extent. It is therefore released through the lungs or, in exceptional cases, through the urine (acetonuria, a symptom of diabetes mellitus). Other ketone bodies are acetylacetone and hydroxymethyl butyrate. These can be processed in the metabolism.

Complex chemistry

Due to its polar carbonyl group, acetone can also form complex compounds with cations.

swell

  1. abc ESIS-European chemical Substances Information System

Safety data sheets

  • Acros
  • Alfa Aesar
  • Carl Roth
  • Mallinckrodt Baker
  • Merck

Categories: Flammable Substance | Lovely substance | Ketone