2-Chloro-5-(chloromethyl)pyridine → 2-Chloro-5-[(methylthio)methyl]pyridine

Beteiligte Stoffe

Reaktionsschritte

A solution of 5-chloromethyl-2-chloropyridine (8.1 g, 50 mmol) in ethanol (50 mL) was added to a suspension of sodium thiomethoxide solid (4.2 g, 60 mmol) in 100 mL ethanol under stirring. An exothermic reaction was observed during the addition and the mixture was then stirred at room temperature overnight. The solvent ethanol was removed under reduced pressure and the residue was re-dissolved in ether-EtOAc solvent and mixed with brine. The two phases were separated and the organic layer was dried over anhydrous Na2SO4, filtered, concentrated and purified by eluting through a silica gel plug with 40% EtOAc in hexane to give 8.14 g of 2-chloro-5-[(methylthio)methyl]pyridine (A) as a colorless oil in 94% yield. The product was analytically pure and directly used for the next step reaction. 1H NMR (300 MHz, CDCl3) δ 8.28 (dd, 1H), 7.65 (dd, 1H), 7.30 (d, 1H), 3.63 (s, 2H), 2.00 (s, 3H).

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