Carbon Dioxide → 4-Ethoxy-3-hydroxypyridine-2-carboxylic acid

A stirred solution of 11 (2.9 g) in THF (50 mL) under an argon atmosphere was cooled to ≦−70 ° C. To this was slowly added t-BuLi (8 mL, 1.5M pentane solution) while keeping the reaction temperature at ≦−66 ° C. After the addition was complete, the mixture was stirred at ≦−70 ° C. for 45 minutes and then poured into a slurry of crushed dry ice in ether. The resulting mixture was stirred until it reached room temperature, then the solvents were evaporated. THF (25 mL) and 4N HCl (15 mL) were added to the residue and the resulting mixture was stirred at room temperature for two hours. At the end of this period, the insoluble material was filtered, washed with a small volume of THF and air dried to give the title compound as a white solid (1.05 g).

1. customat ≦−66 ° C
2. additionAfter the addition
3. stirringThe resulting mixture was stirred until it
4. customreached room temperature
5. customthe solvents were evaporated
6. additionTHF (25 mL) and 4N HCl (15 mL) were added to the residue
7. stirringthe resulting mixture was stirred at room temperature for two hours
8. filtrationAt the end of this period, the insoluble material was filtered
9. washwashed with a small volume of THF and air
10. customdried

ORD record

ord-1e977c491e804b3e81bdffd8ed28398c

Source dataset

uspto-grants-2003_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06521622B1