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

HRID 2110974Notes

Reaction equation

HRID 2110974 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-678f340c6b884a2d89d27849f85ca94d
Source dataset
uspto-grants-2009_04
Patent number
US07517992B2

Reaction notes

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