3-Bromo-5-((triisopropylsilyloxy)methyl)pyridine → 3-Tert-butyl-5-((triisopropylsilyloxy)methyl)pyridine

Participants

Reaction Conditions

Reaction Steps

A mixture of anhydrous CuCN (3.41 g, 38.03 mmol) in 150 mL of anhydrous THF, and ethereal tert-butylmagnesium bromide (38 mL, 76.1 mmol) was stirred under N2 at −78° C. for 20 min. 3-bromo-5-((triisopropylsilyloxy)methyl)pyridine (3.274 g, 9.51 mmol) in THF was added, and the reaction mixture was stirred for 2-3 h at −78° C. and then overnight at room temperature. The reaction mixture was quenched by dropwise addition of saturated aqueous NH4OH and the pH was adjusted to 10 by using 1 M aqueous NaOH, and the resulting solution was extracted with extracted with EtOAc (3×75 mL). The combined organic extracts were dried (Na2SO4,), and concentrated under vacuum to get a residue which was purified by flash column chromatography to give 3-tert-butyl-5-((triisopropylsilyloxy)methyl)pyridine (0.7 g). 1H NMR shows the products contain the desired product and bromine-removed product. 1H NMR (CDCl3): d: 1.124 (m, 22H), 1.369 (s, 5H), 4.878 (s, 2H), 7.298 (m, 0.5H), 7.738 (m, 1H), 8.414 (s, 0.6H), 8.607 (m, 1.5H).

Provenance & Evidence