Propargyl bromide → 5-Hydroxy-7-propargyloxy-2,2-dimethyl-4-chromanone

HRID 1607642Notes

Reaction equation

HRID 1607642 reaction equation
C(=O)([O-])[O-].[K+].[K+].[CH2:7](Br)[C:8]#[CH:9].[OH:11][C:12]1[CH:21]=[C:20]([OH:22])[CH:19]=[C:18]2[C:13]=1[C:14](=[O:25])[CH2:15][C:16]([CH3:24])([CH3:23])[O:17]2>CC(CC)=O.[I-].[K+]>[OH:11][C:12]1[CH:21]=[C:20]([O:22][CH2:9][C:8]#[CH:7])[CH:19]=[C:18]2[C:13]=1[C:14](=[O:25])[CH2:15][C:16]([CH3:23])([CH3:24])[O:17]2

Participants

6

Reactant 3

HCID 7842Propargyl bromideHCID 11430Potassium CarbonateHCID 8213625,7-Dihydroxy-2,2-dimethylchroman-4-one

Product 1

HCID 145929635-Hydroxy-7-propargyloxy-2,2-dimethyl-4-chromanoneYield 75%

Reagents, catalysts & solvents 2

HCID 4875Potassium IodideCatalystHCID 6569Methyl Ethyl KetoneSolvent

Conditions

Temperature
0 °C

Procedure

In 60 ml of methyl-ethyl-ketone 4.2 g of 5,7-dihydroxy-2,2-dimethyl-4-chromanone are dissolved, whereupon 3.0 g (22 millimoles) of potassium carbonate, 0.2 g of potassium iodide, and 3.0 g (2.3 ml, 25 millimoles) of propargyl bromide are added and the reaction mixture is refluxed for 4 hours. The inorganic salt is filtered off, the residue is taken up in 100 ml of carbon tetrachloride and extracted twice with 25 ml of a 5% sodium hydroxide solution each. The aqueous-alkaline layer is cooled to 0° C. The precipitated sodium phenolate salt is filtered off, washed twice with 20 ml of acetone each, and suspended in 25% hydrochloric acid (50 ml). The mixture is stirred at 5° C. for an hour. The precipitated white product is filtered off, washed twice with 20 ml of water each and dried to constant weight. The crude product thus obtained can be directly subjected to further reactions. Thus 3.7 g of the desired compound are obtained, yield 75%, Mp.: 122°-124° C.

Workup

  1. additionare added
  2. temperaturethe reaction mixture is refluxed for 4 hours
  3. filtrationThe inorganic salt is filtered off
  4. extractionextracted twice with 25 ml of a 5% sodium hydroxide solution each
  5. filtrationThe precipitated sodium phenolate salt is filtered off
  6. washwashed twice with 20 ml of acetone each, and
  7. filtrationThe precipitated white product is filtered off
  8. washwashed twice with 20 ml of water each and
  9. customdried to constant weight
  10. customThe crude product thus obtained can

Sources & evidence

ORD record
ord-04ea7f2026104fa39f4452411286b6a4
Source dataset
uspto-grants-1989_09
Patent number
US04866089

Reaction notes

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