Metallation of 3-Methylpyridine

Since 3-methylpyridine is less acidic than diisopropylamine (see Sect. 1), the lateral metallation with LDA is expected to give an equilibrium mixture of 3-lithiomethylpyridine and LDA. The position of this equilibrium may depend to some extent upon the solvent addition of the dipolar aprotic HMPT as a co-solvent (compare Sect. 2, Ref. [3]) presumably will cause a shift in favour of the metallated 

3-Methylpyridine (0.22 mol, 20.5 g, dried over machine-powdered KOH and subsequently filtered) is added over a few s to a solution of 0.2 mol of LDA (see Yol. 

Reaction of the solution of 3-lithiomethylpyridine with acetaldehyde, dimethyl disulfide (inversed-order) and chlorotrimethylsilane gave the products in poor ( 10%) yields. 

Functionalization with n-butyl bromide, chlorotrimethylsilane and dimethyl disulfide. 

If dimethyl disulfide is added dropwise, the desired product is obtained in low yield. The main product is the bis-methylthio derivative, formed by proton transfer from the initial product and subsequent introduction of a second methylthio group. 

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