2,6-Lutidine → N-(4-chloro-5-formylpyridin-2-yl)acetamide

Participants

Reaction Steps

To a stirred solution of N-(4-chloro-5-vinylpyridin-2-yl)acetamide (6 g, 30.5 mmol) and 2,6-lutidine (7.11 mL, 61.0 mmol) in a mixture of 1,4-dioxane (110 mL) and water (25 mL) at 0° C. was added osmium tetroxide (2.5% in 2-methyl-2-propanol, 9.58 mL, 30.5 mmol) followed by the addition of sodium periodate (19.58 g, 92 mmol) and the reaction was stirred for 4 h. The reaction mixture was diluted with water and extracted with EtOAc (2×100 mL). The combined organic layers were washed with brine solution, dried over sodium sulfate, concentrated under reduced pressure and residue so obtained was purified by comb flash column 120 g silica column using hexane/EtOAc as eluant. The desired product was isolated at 30% EtOAc in hexane. The required fractions were concentrated under reduced pressure to yield N-(4-chloro-5-formylpyridin-2-yl)acetamide as a off-white solid (5.8 g, 28.1 mmol, 92% yield). LC/MS (ESI) m/e 197.0 [(M)−, calcd for C8H6ClN2O2 197.04] LC/MS retention time (method A): tR=1.21 min; 1H NMR (400 MHz, DMSO-d6) δ 11.20 (s, 1H), 10.18 (s, 1H), 8.76 (s, 1H), 8.27 (s, 1H), 2.16 (s, 3H).

Provenance & Evidence