Lithium diisopropylamide Chemical Properties

Melting point:

decomposes [MER06]

Boiling point:

65 °C

Density 

0.864 g/mL at 25 °C (lit.)

vapor density 

>1 (vs air)

Flash point:

91 °F

storage temp. 

2-8°C

solubility 

soluble in ethyl ether; insoluble in hydrocarbon solvents

form 

liquid

color 

brown

Water Solubility 

decomposes

Sensitive 

Air & Moisture Sensitive

Merck 

14,3196

BRN 

3655042

CAS DataBase Reference

4111-54-0(CAS DataBase Reference)

EPA Substance Registry System

2-Propanamine, N-(1-methylethyl)-, lithium salt (4111-54-0)

Safety Information

Hazard Codes 

C,N,F

Risk Statements 

14-17-34-67-65-51/53-35-19-15-11-50/53-14/15-10-40-23/24/25-62-63-37-48/20

Safety Statements 

26-36/37/39-43-45-60-61-62-8-16-23-33-27

RIDADR 

UN 3399 4.3/PG 2

WGK Germany 

3

F 

1-10

TSCA 

Yes

HazardClass 

4.2

PackingGroup 

I

HS Code 

29211990

MSDS

• Language:English Provider:SigmaAldrich
• Language:English Provider:ACROS

Lithium diisopropylamide Usage And Synthesis

Chemical Properties

Lithium diisopropylamide (LDA) is a white pyrophoric powder. Freshly prepared, it is soluble in hydrocarbons (in hexane about 10 %), but it tends to precipitate irreversibly from solution as a polymer on heating or prolonged storage. In ethers the solubility is much higher, but with the exception of tetrahydropyran, LDA is decomposed at a rate depending on the ether, concentration, and temperature.
Lithium diisopropylamide can be conveniently prepared from butyllithium and diisopropylamine or purchased as a 2 mol/L (25 %) solution in THF and a mixture of various hydrocarbons. Although LDA is unstable in pure THF (at room temperature a 25% solution loses about 1% of its activity per day), the commercially available compositions containing only a limited amount of THF are satisfactory stable for technical applications.

Chemical Properties

dark yellow to orange or dark red-brown solution. Lithium Diisopropylamide (LDA) [4111- 54-0], LiN(CH(CH3)2)2, Mr 107.14 is a white pyrophoric powder. Freshly prepared, it is soluble in hydrocarbons (in hexane about 10 %), but it tends to precipitate irreversibly from solution as a polymer on heating or prolonged storage. In ethers the solubility is much higher, but with the exception of tetrahydropyran, LDA is decomposed at a rate depending on the ether, concentration, and temperature.

Uses

pH adjuster in colognes and toilet waters. In organic synthesis, particularly, the lithium salt.

Uses

Lithium diisopropylamide is a sterically hindered nonnucleophilic strong base used for selective deprotonations, especially for the production of kinetic enolates (i.e., the thermodynamically less favored isomer) and (hetero-)aromatic carbanions. In the production of the serum lipid regulating agent Gemfibrozil one key intermediate is formed by quenching an ester enolate with 1-bromo-3-chloropropane.

Uses

Lithium diisopropylamide solution (LDA) can be used:

• As an initiator in the anionic polymerization of D,L-lactide and methyl methacrylate.
• To facilitate ester enolization.
• To convert carboxylic acids to enediolate intermediates for preparing trifluoromethyl ketones.
• In ortho-lithiation of arylsulfonyloxazolidinones to prepare N-substituted saccharin analogs.
• To catalyze ortholithiation and Fries rearrangement of aryl carbamates.
• As a promoter in the isomerization of allylic ethers to (Z)-propenyl ethers.

Synthesis

Lithium diisopropylamide has been synthesized by two classical routes. Th 1ost widely adopted route involves in situ formation by deprotonation of diisopropylamineby an alkyllithium reagent, such as butyllithium.Addition of a solutionof butyllithium (in hexane) to a stirred solution of diisopropylamine (freshly distilledfrom CaCl) in tetrahydrofuran directly gives the required solution of lithium diisopropylamide in tetrahydrofuran. This deprotonation process has been reported to be efficient over a wide temperature range (from -78°C to 25°C). The resulting solution of lithium diisopropylamide in tetrahydrofuran appears to be stable, and consequently canbe stored at room temperature for a short period without loss of basicity.
Lithium diisopropylamide can also be synthesized directly by addition of lithium todiisopropylamine.This approach gives better quality crystalline lithium diisopropylamide, especially if required for single-crystal X-raystructure determination, than the butyllithium route.The synthesis of lithium diiso-propylamide by in situ deprotonation of diisopropylamine in tetrahydrofuran by analkyllithium reagent is, however, the most commonly used method.Butyllithium isusually the alkyllithium of choice, but otheralkyllithiums have been used (e.g., MeLi)

General Description

This material is in a solution of THF/Hexanes (ca. 1:7 ratio, respectively)

Flammability and Explosibility

Spontaneously flammable in air (pyrophoric)

Purification Methods

It is purified by refluxing over Na wire or NaH for 30minutes and then distilled into a receiver under N2. Because of the low boiling point of the amine, a dispersion of NaH in mineral oil can be used directly in this purification without prior removal of the oil. It is HIGHLY FLAMMABLE, and is decomposed by air and moisture. [Wittig & Hesse Org Synth 50 69 1970, Beilstein 4 H 154, 4 I 369, 4 II 630, 4 III 274, 4 IV 510.]

Lithium diisopropylamide(4111-54-0)Related Product Information

• Diisopropylamine
• Lithium amide
• N,N-Diisopropylethylamine
• Lithium oxide
• Lithium bis(trimethylsilyl)amide
• DIISOPROPYL ZINC 1.0M SOLUTION IN TOLU&
• N-Methyl-2-pyrrolidone
• N,N'-Diisopropylcarbodiimide
• Lithium chloride
• Lithium
• LITHIUM DIMETHYLAMIDE
• LITHIUM DIETHYLAMIDE
• Isopropylamine
• Lithium diisopropylamide mono(tetrahydrofuran) complex solution
• Lithium diisopropylamide mono(tetrahydrofuran)
• LITHIUM TETRAMETHYLPIPERIDIDE
• LITHIUM DICYCLOHEXYLAMIDE
• Lithium diisopropylamide