Dimethyl Sulfoxide → Methyl 6-formylpyridine-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 2M oxalyl chloride/dichloromethane (236 mL, 462 mmol) in dichloromethane (800 mL) at −45° C. was slowly added dimethylsulfoxide (48.4 mL, 682 mmol) keeping temperature below −45° C. The mixture was stirred for 30 minutes at −45° C. after the addition, and a solution of the product of Example 50-1 (46 g, 276 mmol) in dichloromethane (160 mL) was added dropwise, stirred for 30 minutes at −45° C., treated with triethylamine (175 mL, 1256 mmol), stirred for 15 minutes at −45° C., removed dry ice bath, stirred at −40 to −50 C for 30 minutes, and quenched with pH 7 phosphate buffer solution (250 mL). The organic layer was separated and concentrated. This residue was heated to dissolve in ethyl acetate (100 mL), cooled to room temperature, stirred at room temperature for 1-2 hours and 1 hour at 0° C. The resulting precipitate was filtered and washed with cold ethyl acetate (100 mL) to give the title compound (30 g, 69%). 1H NMR (CDCl3) δ ppm 4.07 (s, 3 H), 8.05 (m, 1 H), 8.16 (m, 1 H), 8.36 (m, 1 H), 10.18 (d, 1 H).

Provenance & Evidence