4-(Methylthio)benzyl bromide → Ammonium Hydroxide

Beteiligte Stoffe

Reaktionsschritte

A solution of 1-(bromomethyl)-4-(methylsulfanyl)benzene (prepared according to D. D. M. Wayner, D. R. Arnold, Can J. Chem., 1984, 62, 1164) (2.54 g, 11.7 mmol) in THF (10 mL) was added dropwise to a slurry of Riecke® Zinc in THF (22.8 mL of a commercial suspension [5 g Zn/100 mL], 17.5 mmol) under nitrogen. During this time the temperature rose steadily to 35° C. After allowing the black slurry to cool to room temperature over 30 min bis(triphenylphosphine)nickel (II) chloride (762 mg, 1.17 mmol) was added followed by a solution of methyl 3-chloroisonicotinate (prepared according to J. Epsztajn, M. W. Plotka, A. Grabowska, Synth. Commun., 1997, 27, 1075) (1.0 g, 5.83 mmol) in THF (10 mL), dropwise, taking care to keep the temperature below 30° C. After the addition was complete the reaction was allowed to cool to room temperature over 1 h before being quenched by the addition of sat. NH4Cl (aq) (20 mL) while cooling with an ice bath. The mixture was filtered through Celite®, washing well with EtOAc (3×20 mL), the organic layer was separated, dried (MgSO4) and evaporated to give a brown oil. The residue was purified by column chromatography [SiO2; EtOAc:pentane, 1:3 increasing polarity to EtOAc:pentane, 1:1 and then to (EtOAc:MeOH:NH4OH, 95:5:0.5):pentane, 1:1] to give the title compound as an orange oil; δH (CDCl3, 400 MHz) 2.43 (3H, s), 3.82 (3H, s), 4.30 (2H, s), 7.05 (2H, d), 7.18 (2H, d), 7.67 (1H, br), 8.59 (2H, br); MS m/z (TS+) 274 (MH+).

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