Question

n- butyl lithium is prepared from

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Answer 1

Answer:

The standard preparation for n-BuLi is reaction of 1-bromobutane or 1-chlorobutane with Li metal:[3]

2 Li + C4H9X → C4H9Li + LiX

where X = Cl, Br

If the lithium used for this reaction contains 1–3% sodium, the reaction proceeds more quickly than if pure lithium is used. Solvents used for this preparation include benzene, cyclohexane, and diethyl ether. When BuBr is the precursor, the product is a homogeneous solution, consisting of a mixed cluster containing both LiBr and BuLi, together with a small amount of octane. BuLi forms a weaker complex with LiCl, so that the reaction of BuCl with Li produces a precipitate of LiCl.

Solutions of butyllithium, which are susceptible to degradation by air, are standardized by titration. A popular weak acid is biphenyl-4-methanol, which gives a deeply colored dilithio derivative at the end point.[6]