2-Indanone → 1,4-dihydro-3H-2-benzopyran-3-one

HRID 2107795Notes

Reaction equation

HRID 2107795 reaction equation
[CH2:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH2:3][C:2]1=[O:10].C(=O)(O)[O-:12].[Na+].ClC1C=C(C=CC=1)C(OO)=O.[O-]S([O-])(=S)=O.[Na+].[Na+]>ClCCl>[CH2:1]1[C:9]2[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=2[CH2:3][C:2](=[O:10])[O:12]1

Participants

6

Reactant 4

HCID 119832-IndanoneHCID 24477Sodium ThiosulfateHCID 70297m-Chloroperbenzoic acidHCID 516892Sodium Bicarbonate

Product 1

HCID 780921,4-dihydro-3H-2-benzopyran-3-oneYield 90.4%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
20 °C

Procedure

To 6.60 g (0.050 mol) of 2-indanone in 50 mL of dry dichloromethane was added 38.0 g (0.45 mol) of powdered anhydrous sodium bicarbonate, followed by 17.0 g (0.10 mol) of m-chloroperoxybenzoic acid. After stirring at 20° C. for 20 hours, further 3.0 g (0.017 mol) of the peracid was added and stirring continued for 24 hours. After addition of 200 mL of 10% aqueous Na2S2O3 stirring was continued until two clear phases had formed. The organic solution was separated and the aqueous phase was extracted with two 100 mL portions of dichloromethane. The combined organic solutions were dried (MgSO4) and concentrated under vacuum at 30° C. Solution in a mixture of ether and pentane, filtration and concentration under vacuum gave 6.7 g (90%) of 1,4-dihydro-3H-2-benzopyran-3-one, which could be recrystallized from ether or sublimed at 30°-40° C. (0.24 mm); mp 78°-79° C.; TLC Rf 0.36 (SiO2, CH2Cl2, brown-orange with iodine).

Workup

  1. stirringstirring
  2. waitcontinued for 24 hours
  3. customhad formed
  4. customThe organic solution was separated
  5. extractionthe aqueous phase was extracted with two 100 mL portions of dichloromethane
  6. dry with materialThe combined organic solutions were dried (MgSO4)
  7. concentrationconcentrated under vacuum at 30° C
  8. additionSolution in a mixture of ether and pentane, filtration and concentration under vacuum

Sources & evidence

ORD record
ord-6c41e366f6cb4e519880c802768204aa
Source dataset
uspto-grants-1990_06
Patent number
US04935509

Reaction notes

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