Hydrochloric Acid → 2,2,5,7-Tetramethylchroman-6-thiol

HRID 2081806Notes

Reaction equation

HRID 2081806 reaction equation
[H-].[Al+3].[Li+].[H-].[H-].[H-].[CH3:7][C:8]1([CH3:23])[CH2:17][CH2:16][C:15]2[C:10](=[CH:11][C:12]([CH3:22])=[C:13]([S:19]C#N)[C:14]=2[CH3:18])[O:9]1.O.Cl>CCOCC>[CH3:7][C:8]1([CH3:23])[CH2:17][CH2:16][C:15]2[C:10](=[CH:11][C:12]([CH3:22])=[C:13]([SH:19])[C:14]=2[CH3:18])[O:9]1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 962WaterHCID 197807302,2,5,7-Tetramethyl-6-thiocyanatochromanHCID 21226445Aluminium lithium hydride

Product 1

HCID 197806892,2,5,7-Tetramethylchroman-6-thiol

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent3×

Conditions

Temperature
15 °C

Procedure

Lithium aluminum hydride (2.65 g, 69.6 mM) was suspended in anhydrous ether (165 ml) under an atmosphere of argon with external cooling to 15° C. A solution of the thiocyanate (A) (8.6 g, 34.8 mM) in anhydrous ether (100 ml) was added dropwise during 30 minutes and the mixture was then heated under reflux for 30 minutes. The reaction mixture was cooled and ether (80 ml) was added. Water (80 ml) was then added cautiously dropwise followed by 2M hydrochloric acid (120 ml). The organic layer was separated and combined with a further extract. The combined organic phase was washed with saturated sodium bicarbonate solution and then with brine. Evaporation of the solvent gave 2,2,5,7-tetramethylchroman-6-thiol (B) as a clear oil which was used without further purification.

Workup

  1. temperaturethe mixture was then heated
  2. temperatureunder reflux for 30 minutes
  3. temperatureThe reaction mixture was cooled
  4. customThe organic layer was separated
  5. washThe combined organic phase was washed with saturated sodium bicarbonate solution
  6. customEvaporation of the solvent

Sources & evidence

ORD record
ord-0e214f333ae840308136d6de69b90d75
Source dataset
uspto-grants-1993_02
Patent number
US05185452

Reaction notes

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