2,3-Dichloropropene → 7-[(2-Chloroprop-2-en-1-yl)oxy]-4,8-dimethyl-2H-1-benzopyran-2-one

HRID 1855733Notes

Reaction equation

HRID 1855733 reaction equation
[CH3:1][C:2]1[C:11]2[C:6](=[C:7]([CH3:13])[C:8]([OH:12])=[CH:9][CH:10]=2)[O:5][C:4](=[O:14])[CH:3]=1.C(=O)([O-])[O-].[K+].[K+].[Cl:21][C:22]([CH2:24]Cl)=[CH2:23]>CC(C)=O>[CH3:1][C:2]1[C:11]2[C:6](=[C:7]([CH3:13])[C:8]([O:12][CH2:24][C:22]([Cl:21])=[CH2:23])=[CH:9][CH:10]=2)[O:5][C:4](=[O:14])[CH:3]=1

Participants

5

Reactant 3

HCID 65652,3-DichloropropeneHCID 11430Potassium CarbonateHCID 53565972H-1-Benzopyran-2-one, 7-hydroxy-4,8-dimethyl-

Product 1

HCID 132080597-[(2-Chloroprop-2-en-1-yl)oxy]-4,8-dimethyl-2H-1-benzopyran-2-oneYield 77%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

A mixture of 4,8-dimethyl-7-hydroxycoumarin (8.00 g., 42.1 m mole); anhydrous potassium carbonate (18.1 g., 130 m mole); 2,3-dichloropropene (33.6 g., 302 m mole); and acetone (600 ml.) was stirred and heated under reflux for twenty-four hours. The reaction mixture was concentrated to ca. 200 ml., filtered, and the inorganic salts were washed with acetone. Evaporation of the combined filtrate and washing under reduced pressure left a tan-colored residue (11.30 g.). Recrystallization from aqueous methanol gave a 77% yield of 4,8-dimethyl-7-(2'-chloroallyloxy)coumarin as small, off-white needles (8.55 g., m.p. 117.5°-120° C.). Another recrystallization did not change the m.p. but gave an analytical sample.

Workup

  1. temperatureheated
  2. temperatureunder reflux for twenty-four hours
  3. concentrationThe reaction mixture was concentrated to ca. 200 ml
  4. filtration, filtered
  5. washthe inorganic salts were washed with acetone
  6. customEvaporation of the combined filtrate
  7. washwashing under reduced pressure
  8. waitleft a tan-colored residue (11.30 g.)
  9. customRecrystallization from aqueous methanol

Sources & evidence

ORD record
ord-1852563eaf574bd892fe0bd5951f91e6
Source dataset
uspto-grants-1980_08
Patent number
US04216154

Reaction notes

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