Sodium Carbonate → 6-Chloro-3-cyano-2-(4-nitro-phenoxycarbonylmethyl)-pyridine 1-oxide

Another batch was prepared as follows: To a suspension of (6-chloro-3-cyano-pyridin-2-yl)-acetic acid 4-nitro-phenyl ester (157 mg, 0.5 mmol) and sodium percarbonate (157 mg, 1.0 mmol) in anhydrous acetonitrile (4 mL), cooled in an ice-water bath, was added trifluoromethanesulfonic anhydride dropwise (253 μL, 1.5 mmol). The reaction mixture turned into a translucent light yellow solution. After stirring for 3 hrs in ice-water bath, the reaction mixture was poured into saturated sodium carbonate solution (30 mL) and cooled in an ice-water bath. The reaction vial was rinsed with DCM and poured into the sodium carbonate solution. After stirring for 25 min in the ice-water bath, the organic layer was separated. The aqueous layer was further extracted with DCM (2×15 mL). The combined organic layers were dried over anhydrous sodium sulfate. After rotary evaporation of most solvent, the concentrated solution was loaded on a preparative silica TLC (2 mm, 20×20 cm) and developed with EtOAc/Hexane (1:1). The title compound was obtained as a light yellow solid (108 mg, 65%). 1H-NMR (300 MHz, CDCl3) δ 8.29 (d, 2H), 7.68 (d, 1H), 7.51 (d, 1H), 7.31 (d, 2H), 4.40 (d, 2H).

1. customAnother batch was prepared
2. temperaturecooled in an ice-water bath
3. temperaturecooled in an ice-water bath
4. customThe reaction
5. washvial was rinsed with DCM
6. additionpoured into the sodium carbonate solution
7. customthe organic layer was separated
8. extractionThe aqueous layer was further extracted with DCM (2×15 mL)
9. dry with materialThe combined organic layers were dried over anhydrous sodium sulfate
10. customAfter rotary evaporation of most solvent

ORD-Eintrag

ord-2eaf860763c04078a867cbfb2ed2c484

Quelldatensatz

uspto-grants-2010_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07829584B2