Water → 3,4-Dihydro-2H-1-benzothiopyran-4-ol

HRID 2084338Notes

Reaction equation

HRID 2084338 reaction equation
[S:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[C:4](=[O:11])[CH2:3][CH2:2]1.[H-].[Al+3].[Li+].[H-].[H-].[H-].O.OS(O)(=O)=O>CCOCC>[S:1]1[C:10]2[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=2[CH:4]([OH:11])[CH2:3][CH2:2]1

Participants

6

Reactant 4

HCID 962WaterHCID 1118Sulfuric AcidHCID 19048Thiochroman-4-oneHCID 21226445Aluminium lithium hydride

Product 1

HCID 3751023,4-Dihydro-2H-1-benzothiopyran-4-ol

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

A solution of thiochroman-4-one (9 g) in ether (27 ml) was added slowly to a mixture of lithium aluminium hydride (0.53 g) in ether (54 ml). After the end of the addition, the mixture was refluxed for 2 hours. The reaction mixture was cooled and ice was added, followed by water and by a solution of 20% H2SO4. The water phase was washed twice with ether. The ether phase was washed twice with NaOH 2N, and once with water, dried over MgSO4 and evaporated. The clear oil (8.9 g) crystallised after few hours. Rdt=97%

Workup

  1. additionAfter the end of the addition
  2. temperaturethe mixture was refluxed for 2 hours
  3. temperatureThe reaction mixture was cooled
  4. additionice was added
  5. washThe water phase was washed twice with ether
  6. washThe ether phase was washed twice with NaOH 2N
  7. dry with materialonce with water, dried over MgSO4
  8. customevaporated
  9. customThe clear oil (8.9 g) crystallised after few hours

Sources & evidence

ORD record
ord-a964377c2e80473e97c5c75bcc690004
Source dataset
uspto-grants-2004_04
Patent number
US06716850B2

Reaction notes

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