Dimethyl Sulfoxide → HCID 68814472, compound

Temperature

80 °C

Add 2-chloro-6-methoxy-isonicotinic acid methyl ester (5 g, 24.8 mmol), palladium acetate (4.157 g, 18.5 mmol), 1,4-bis(diphenylphosphino)butane (1.038 g, 2.43 mmol), ethanol (127 mL), triethylamine (18 mL, 129 mmol) with DMSO (150 mL) to a pressure vessel. Seal the pressure vessel and purge with nitrogen. Pressurize the reaction mixture with carbon monoxide (690 KPa), seal the vessel, agitate the reaction and heat to 80° C. for 19 h. Cool to room temperature, filter the reaction mixture through a filtering agent and concentrate. Dissolve the residue in water (200 mL) and extract with hexanes (3×150 mL) and concentrate to give 6-methoxypyridine-2,4-dicarboxylic acid 2-ethyl ester 4-methyl ester (3.5 g). Extract the aqueous layer with ethyl acetate (3×150 mL) and wash the combined ethyl acetate layers with water, aqueous sodium bicarbonate solution, saturated aqueous sodium chloride, dry (sodium sulfate), concentrate, and purify (silica gel chromatography, eluting with ethyl acetate and hexanes) to give additional title compound (2.1 g) (5.6 g, 95% combined yield).

1. customSeal the pressure vessel
2. custompurge with nitrogen
3. customseal the vessel
4. customthe reaction
5. temperatureCool to room temperature
6. filtrationfilter the reaction mixture through a filtering agent
7. concentrationconcentrate
8. dissolutionDissolve the residue in water (200 mL)
9. extractionextract with hexanes (3×150 mL)
10. concentrationconcentrate

ORD record

ord-97cb404641584187af93e93f08104997

Source dataset

uspto-grants-2009_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07618978B2