Phosphoric Acid → Ristianol

HRID 1389785Notes

Reaction equation

HRID 1389785 reaction equation
[SH:1][CH2:2][CH2:3][OH:4].C[O-].[Na+].Br.[N:9]1[CH:14]=[CH:13][C:12]([CH2:15]Br)=[CH:11][CH:10]=1.P(=O)(O)(O)O>C(O)C>[OH:4][CH2:3][CH2:2][S:1][CH2:15][C:12]1[CH:13]=[CH:14][N:9]=[CH:10][CH:11]=1

Participants

6

Reactant 4

HCID 1004Phosphoric AcidHCID 15672-MercaptoethanolHCID 10942334Sodium MethoxideHCID 127522194-(Bromomethyl)pyridine hbr

Product 1

HCID 54050Ristianol

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

In an alternative procedure, 2-mercaptoethanol (11.9 g., 0.152 mole) was dissolved in 138.5 ml. of absolute ethanol and cooled to 18° C. Sodium methoxide (15.7 g., 0.291 mole) was added; the temperature rose to 38° C. and a clear solution resulted. The reaction mixture was cooled somewhat and, while maintaining the temperature below 30° C., 4-picolyl bromide hydrobromide (35 g., 0.138 moles) was added portionwise over 10 minutes. The reaction mixture was then heated to reflux and refluxed for 80 minutes. The reaction was concentrated to a thick mass, which was dissolved in 140 ml. of water and extracted twice with 140 ml. of ethyl acetate. Salt was dissolved in the aqueous phase during the second extraction. The combined ethyl acetate extracts were back washed twice with 150 ml. of 1 N NaOH, dried over anhydrous magnesium sulfate, filtered, and concentrated to about half-volume. While maintaining the temperature between 30° and 35° C., phosphoric acid (12.0 g., 0.122 moles) was added very slowly to directly precipitate crude product as the dihydrogen phosphate salt, recovered by filtration after stirring for 1 hour. The crude was recrystallized from absolute ethanol, yielding purified 4-(2-hydroxyethylthiomethyl)pyridinium dihydrogen phosphate (14.0 g.).

Workup

  1. customrose to 38° C.
  2. customa clear solution resulted
  3. temperatureThe reaction mixture was cooled somewhat
  4. additionwas added portionwise over 10 minutes
  5. temperatureThe reaction mixture was then heated
  6. temperatureto reflux
  7. temperaturerefluxed for 80 minutes
  8. concentrationThe reaction was concentrated to a thick mass, which
  9. dissolutionwas dissolved in 140 ml
  10. extractionof water and extracted twice with 140 ml
  11. dissolutionSalt was dissolved in the aqueous phase during the second extraction
  12. washThe combined ethyl acetate extracts were back washed twice with 150 ml
  13. dry with materialof 1 N NaOH, dried over anhydrous magnesium sulfate
  14. filtrationfiltered
  15. concentrationconcentrated to about half-volume
  16. filtrationrecovered by filtration
  17. customThe crude was recrystallized from absolute ethanol
  18. customyielding
  19. custompurified 4-(2-hydroxyethylthiomethyl)pyridinium dihydrogen phosphate (14.0 g.)

Sources & evidence

ORD record
ord-205c07753ad24277b27c9d92a69a5711
Source dataset
uspto-grants-1981_01
Patent number
US04246263

Reaction notes

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