Hydrogen Sulfide → 5-Hydroxynicotinic acid

To 10.1 g (0.05 mol) of 5-bromonicotinic acid was added 10 g of NaOh dissolved in 63 mL of water, 3.1 g of coppersulfate pentahydrate and 0.42 g of copper (0). The reaction mixture was vigorously stirred and heated under reflux for 30 hours. After cooling the mixture to room temperature, 4.8 g of Na2S.H2O was added and stirring was pursued overnight. The reaction mixture was heated to 70° C. and treated with H2S gas until disappearance of the white precipitate (3 h). After cooling to room temperature, the mixture was filtered and the pH of the filtrate was adjusted to 5.2 with concentrated hydrochloric acid. The precipitate was filtered and the pH of the % filtrate was adjusted to 4.6 with concentrated hydrochloric acid. The white precipitate was then filtered, washed with water and dried under reduced pressure giving 4.3 g (yield: 62%) of product of molecular formula C7H5NO3. Aspect: white powder.

1. temperatureheated
2. temperatureunder reflux for 30 hours
3. stirringstirring
4. temperatureThe reaction mixture was heated to 70° C.
5. temperatureAfter cooling to room temperature
6. filtrationthe mixture was filtered
7. filtrationThe precipitate was filtered
8. filtrationThe white precipitate was then filtered
9. washwashed with water
10. customdried under reduced pressure

ORD-Eintrag

ord-39e605143a2f487da16c435c9525b943

Quelldatensatz

uspto-grants-2011_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07977354B2