Water → 2,2-Dimethyl-4-(2-thienyl)chroman-7-ol

HRID 26291Notes

Reaction equation

HRID 26291 reaction equation
C[Li].[OH:3][C:4]1C=C2[C:7]([CH:8]([C:15]3[S:16][CH:17]=[CH:18][CH:19]=3)[CH2:9]C(=O)O2)=[CH:6][CH:5]=1.O.[C:21]1(C)C=CC(S(O)(=O)=O)=CC=1.[CH3:32][CH2:33][O:34][CH2:35][CH3:36]>C1C=CC=CC=1>[CH3:32][C:33]1([CH3:21])[CH2:9][CH:8]([C:15]2[S:16][CH:17]=[CH:18][CH:19]=2)[C:7]2[C:35](=[CH:36][C:4]([OH:3])=[CH:5][CH:6]=2)[O:34]1

Participants

7

Reactant 5

HCID 962WaterHCID 3283Diethyl Ether2×HCID 6101p-Toluenesulfonic acidHCID 20570530HCID 20570530, compoundHCID 178418348HCID 178418348, compound

Product 1

HCID 205705122,2-Dimethyl-4-(2-thienyl)chroman-7-ol

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

Methyl-lithium (150 ml of a 2 N solution) was added under dry N2 to a solution of 7-hydroxy-4-(2-thienyl) dihydrocoumarin (14.8 g) in dry ether (120 ml) and the mixture allowed to stand for 3 days. Water (500 ml) was added and the ether layer discarded. The aqueous layer was acidified, extracted with ether and the combined ether layers dried (MgSO4). Removal of the solvent under reduced pressure gave a black oil which was then dissolved in dry benzene (100 ml) containing a trace of p-toluene sulphonic acid. The mixture was heated under reflux for 3 hours in a Dean & Stark apparatus. Removal of the solvent under reduced pressure and chromatography on silica gave the required phenol (7 g).

Workup

  1. extractionextracted with ether
  2. dry with materialthe combined ether layers dried (MgSO4)
  3. customRemoval of the solvent under reduced pressure
  4. customgave a black oil which
  5. temperatureThe mixture was heated
  6. temperatureunder reflux for 3 hours in a Dean & Stark apparatus
  7. customRemoval of the solvent under reduced pressure and chromatography on silica

Sources & evidence

ORD record
ord-6299d1563295424ebe692ace0aca787f
Source dataset
uspto-grants-1979_04
Patent number
US04148909

Reaction notes

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