4111-54-0

dark yellow to orange or dark red-brown solution

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

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)

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.]

Spontaneouslyflammableinair(pyrophoric)