Triethylamine → Deferitrin

HRID 1181638Notes

Reaction equation

HRID 1181638 reaction equation
Cl.[CH3:2][C@:3]([C:7]([OH:9])=[O:8])([CH2:5][SH:6])[NH2:4].[OH:10][C:11]1[CH:18]=[C:17]([OH:19])[CH:16]=[CH:15][C:12]=1[C:13]#N.C(N(CC)CC)C.[OH-].[K+]>C(O)C.O>[OH:10][C:11]1[CH:18]=[C:17]([OH:19])[CH:16]=[CH:15][C:12]=1[C:13]1[S:6][CH2:5][C@:3]([CH3:2])([C:7]([OH:9])=[O:8])[N:4]=1

Participants

7

Reactant 4

HCID 8471TriethylamineHCID 14797Potassium HydroxideHCID 30175202,4-DihydroxybenzonitrileHCID 10080831(S)-2-Methylcysteine hydrochloride

Product 1

HCID 135413558DeferitrinYield 87.6%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

4.00 g (S)-2-methylcysteine hydrochloride (23.3 mmol,1.0 meq) and 3.14 g 2,4-dihydroxy benzonitrile (23.3 mmol, 1.0 meq) were suspended in 40 mL ethanol. After degassing this mixture with nitrogen (30 min) 4.95 g triethylamine (6.8 mL, 48.9 mmol, 2.05 meq) were added. The obtained suspension was heated under reflux in an atmosphere of nitrogen for 20 hours and then cooled to room temperature. From this suspension ethanol was evaporated under reduced pressure until an oil (20% of the initial volume) was obtained. This oil was dissolved in 50 mL water. The solution was adjusted to pH 7.5 with 1.20 ml 20% KOH and was extracted two times each with 20 mL methyl t-butyl ether (MTBE). The aqueous layer was separated, adjusted with 20% KOH to pH 11 and again extracted two times each with 20 mL MTBE. After separating the aqueous layer the pH was set with concentrated HCl to 7.5 and traces of MTBE were distilled off. Then the aqueous solution was acidified with 1.50 ml concentrated HCl to pH 1.5. The product precipitated. This suspension was stirred at 4° C. for 1 hour. Then the precipitate was filtered, washed two times each with 10 mL water (5° C.) and dried at 45° C. under vacuum. The reaction yielded 5.17 g (87.6%) of crude 4,5-dihydro-2-(2,4-dihydroxyphenyl)-4-methylthiazole-4(S)-carboxylic acid product. 1H-NMR showed no significant impurity.

Workup

  1. additionwere added
  2. temperatureThe obtained suspension was heated
  3. temperatureunder reflux in an atmosphere of nitrogen for 20 hours
  4. customFrom this suspension ethanol was evaporated under reduced pressure until an oil (20% of the initial volume)
  5. customwas obtained
  6. extractionwas extracted two times each with 20 mL methyl t-butyl ether (MTBE)
  7. customThe aqueous layer was separated
  8. extractionagain extracted two times each with 20 mL MTBE
  9. customAfter separating the aqueous layer the pH
  10. distillationwere distilled off
  11. customThe product precipitated
  12. filtrationThen the precipitate was filtered
  13. washwashed two times each with 10 mL water (5° C.)
  14. customdried at 45° C. under vacuum

Sources & evidence

ORD record
ord-7744b76f5bcf403e8d873088c1f60a8a
Source dataset
uspto-grants-2007_10
Patent number
US07285676B2

Reaction notes

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