What Is Diisopropanolamine?
Diisopropanolamine is an organic compound classified as a secondary amine.
It is a clear colorless liquid with an amine or ammonia-like odor at room temperature.
Uses of Diisopropanolamine
Diisopropanolamine is widely used as an organic synthetic raw material for pharmaceuticals, dye intermediates, rubber chemicals, herbicides, and surfactants.
As a rubber chemical, it is added as an anti-aging agent in the rubber molding process. This prevents the deterioration of rubber caused by chemical reactions induced by heat, light, and ozone.
As a herbicide, it is used as a hormone-type selective herbicide with auxin-like action. However, it is only used for herbicidal purposes in non-farming areas.
Properties of Diisopropanolamine
Diisopropylamine has the chemical formula C6H15N. It has a melting point of -61°C, boiling point of 84°C, and is a clear, colorless liquid at room temperature. It has an amine or ammonia-like odor. Its molecular weight is 101.193, density 0.722 g/mL, a base dissociation constant pKb of 3.43, and an acid dissociation constant pKa of 11.07 (in water) for conjugated acids.
It is soluble in ethanol, acetone, and other organic solvents, specifically methanol, ether, ethyl acetate, aromatic and aliphatic hydrocarbons, fatty acids, mineral oils, and solid oils. It is also soluble in water.
Types of Diisopropanolamine
Diisopropanolamine is usually sold to the public as a reagent product for research and development. Capacity types include 25mL, 100mL, 500mL, and 2.5L, with different manufacturers offering different volume standards.
They are usually treated as reagent products that can be handled at room temperature. Reagent products are not intended for use other than for research and development purposes..
Other Information on Diisopropanolamine
1. Reactivity of Diisopropanolamine
Diisopropanolamine is a stable substance under normal handling conditions, but reacts violently with oxidizing agents, posing a risk of fire or explosion. It reacts with many compounds, including organic chlorides, nitriles, and oxides.
It is corrosive to copper and zinc and their alloys, galvanized steel, and aluminum, and produces hydrogen gas. When heated or burned, it produces toxic and corrosive fumes and gases such as carbon monoxide, carbon dioxide, and nitrogen oxides.
2. Synthesis of Diisopropanolamine
Diisopropanolamine can be synthesized by reductive amination of acetone. Ammonia is used as a reactant against the raw material acetone in a hydrogen gas atmosphere, and a catalyst such as copper chromite is used.
It is distilled and purified in the presence of potassium hydroxide and can be stored in an inert gas atmosphere in the presence of sodium.
3. Preparation of Lithium Diisopropylamide (LDA)
One of the most important organic synthetic applications of diisopropanolamine is the preparation of lithium diisopropylamide (LDA). Lithium diisopropylamide (LDA) is a substance often used in organic synthesis as a strong base.
It has an acid dissociation constant pKa of about 34 in THF and can withdraw most acidic protons, including alcohols and carbonyl compounds.
Common methods of using LDA in reactions include:
- In a dry ice/acetone bath (or dry ice/methanol bath at -78°C). Add 1 molar equivalent of n-butyl lithium (e.g., hexane solution) to diisopropanolamine in a tetrahydrofuran (THF) solution
- Warm the reaction mixture to 0°C over 15 minutes to prepare the LDA solution in situ.
- Use in subsequent reactions