Eosin → 2-Mercapto-4-Methylpentanoic Acid

HRID 1249343

Reaction equation

HRID 1249343 reaction equation
[OH-].[Na+].C1C=[C:7]([C:9]2[C:23]3C(=C(Br)C([O-])=C(Br)C=3)OC3[C:10]=2C=C(Br)C(C=3Br)=O)[C:6]([C:29]([O-:31])=[O:30])=CC=1.[Na+].[Na+].C(=[S:37])([O-])[O-].[Na+].[Na+]>O>[SH:37][CH:6]([CH2:7][CH:9]([CH3:23])[CH3:10])[C:29]([OH:31])=[O:30]

Participants

5

Reactant 3

HCID 11048EosinHCID 14798Sodium HydroxideHCID 20782767HCID 20782767, compound

Product 1

HCID 136332582-Mercapto-4-Methylpentanoic AcidYield 34%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A total of 1.25 g. (6.5 mmoles) of the product prepared above is taken up in 2 ml. of water. Sufficient 1 N sodium hydroxide is added to dissolve the bromo acid. To this mixture, there is added 5 ml. of 40% sodium thiocarbonate and the vessel is closed and allowed to stand at room temperature for 24 hours. At the end of this period, the solution is acidified with 18 N. sulfuric acid, and extracted with 2 10 ml. portions of ethyl ether. The combined extracts are dried over anhydrous magnesium sulfate and filtered. The filtrate is concentrated to approximately half its volume and chromatographed on a silica gel column (2.2×30 cm). The original solution is eluted with 150 ml. of ethyl ether, and the product recovered by evaporation of the solvent in the eluate. The yield is approximately 34%. The Rf values (TLC) are 0.88 and 1.0 on silica gel and cellulose plates (n-butanol/acetic acid/water-12/3/5).

Workup

  1. additionTo this mixture, there is added 5 ml
  2. extractionsulfuric acid, and extracted with 2 10 ml
  3. dry with materialThe combined extracts are dried over anhydrous magnesium sulfate
  4. filtrationfiltered
  5. concentrationThe filtrate is concentrated to approximately half its volume
  6. customchromatographed on a silica gel column (2.2×30 cm)
  7. washThe original solution is eluted with 150 ml
  8. customof ethyl ether, and the product recovered by evaporation of the solvent in the eluate

Sources & evidence

ORD record
ord-52e99b5cc837459a82e01b3c0512afe2
Source dataset
uspto-grants-1986_12
Patent number
US04631270

Linked notes

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