Dimethyl Sulfoxide → Methyl 6-formylpyridine-2-carboxylate

Temperature

-45 °C

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).

1. customat −45° C.
2. customtemperature below −45° C
3. additionafter the addition
4. stirringstirred for 30 minutes at −45° C.
5. stirringstirred for 15 minutes at −45° C.
6. customremoved dry ice bath
7. stirringstirred at −40 to −50 C for 30 minutes
8. customquenched with pH 7 phosphate buffer solution (250 mL)
9. customThe organic layer was separated
10. concentrationconcentrated
11. temperatureThis residue was heated
12. dissolutionto dissolve in ethyl acetate (100 mL)
13. temperaturecooled to room temperature
14. stirringstirred at room temperature for 1-2 hours and 1 hour at 0° C
15. filtrationThe resulting precipitate was filtered
16. washwashed with cold ethyl acetate (100 mL)

ORD record

ord-7a5be8b819b94484b9bf9343a1539e05

Source dataset

uspto-grants-2010_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07834043B2