3-Methyl-2-butenoic acid → Chromanone

HRID 542221Notes

Reaction equation

HRID 542221 reaction equation
CO[C:3]1[CH:4]=[C:5](O)[CH:6]=[CH:7][C:8]=1[O:9][CH3:10].CC(C)=[CH:14][C:15](O)=[O:16]>C(OCC)C>[CH:5]1[CH:6]=[CH:7][C:8]2[O:9][CH2:10][CH2:14][C:15](=[O:16])[C:3]=2[CH:4]=1

Participants

4

Reactant 2

HCID 109313-Methyl-2-butenoic acidHCID 162513,4-Dimethoxyphenol

Product 1

HCID 68110ChromanoneYield 168.3%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

The amount of 10 g of 3,4-dimethoxyphenol and 7.8 g of 3,3-dimethyl acrylic acid were combined in a 125 ml. erlenmeyer flask and dissolved with the addition of 40 ml anhydrous ethyl ether. The ether was removed in vacuo and while the contents of the flask remained liquid, 50 gm of polyphosphoric acid was added. The flask and contents were placed on a steam bath and heated with stirring for 1 hour. At the end of 1 hour, 75 ml. of water was added and the contents stirred into solution for 5 minutes. The solution was allowed to cool and a substantial sticky precipitate formed. The aqueous layer was decanted and extracted with 100 ml. of ether. The ether extract was washed successively with 150 ml. of water, 100 ml. of 5% sodium carbonate and 100 ml. of saturated NaCl solution. The ether extract was dried over anhydrous sodium sulfate. The sticky residue formed on cooling was dissolved in 300 ml. of chloroform and washed successively with 150 ml. of water, two 150 ml. portions of 5% sodium carbonate solution and 150 ml. of saturated NaCl solution. The chloroform solution was dried over anhydrous sodium sulfate. The ethereal and chloroform extracts were combined and the solvents removed in vacuo leaving 16.17 gm of off-white crystalline chromanone.

Workup

  1. customThe ether was removed in vacuo and while the contents of the flask
  2. additionwas added
  3. customThe flask and contents were placed on a steam bath
  4. temperatureheated
  5. customAt the end of 1 hour, 75 ml
  6. additionof water was added
  7. stirringthe contents stirred into solution for 5 minutes
  8. temperatureto cool
  9. customa substantial sticky precipitate formed
  10. customThe aqueous layer was decanted
  11. extractionextracted with 100 ml
  12. extractionThe ether extract
  13. washwas washed successively with 150 ml
  14. extractionThe ether extract
  15. dry with materialwas dried over anhydrous sodium sulfate
  16. customThe sticky residue formed
  17. temperatureon cooling
  18. dissolutionwas dissolved in 300 ml
  19. washof chloroform and washed successively with 150 ml
  20. dry with materialThe chloroform solution was dried over anhydrous sodium sulfate
  21. customthe solvents removed in vacuo

Sources & evidence

ORD record
ord-e7e9ca4cc9594384a44829b16e3f6f44
Source dataset
uspto-grants-1987_04
Patent number
US04656189

Reaction notes

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