Pentane → Chroman

HRID 542223Notes

Reaction equation

HRID 542223 reaction equation
[CH3:1][C:2](C)=CCBr.[CH2:7]1[O:15][C:14]2[CH:13]=[CH:12][C:11](O)=[CH:10][C:9]=2O1.CCCCC>[Cl-].[Cl-].[Zn+2].C1C=CC=CC=1>[O:15]1[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[CH2:2][CH2:1][CH2:7]1

Participants

6

Reactant 3

HCID 8003PentaneHCID 68289SesamolHCID 700922-Butene, 1-bromo-3-methyl-

Product 1

HCID 136319ChromanYield 190.4%

Reagents, catalysts & solvents 2

HCID 3007855ZincchlorideCatalystHCID 241BenzeneSolvent

Procedure

5.1 gm of 3-methyl-1-bromo-2-butene was combined with 4 gm of 3,4-methylenedioxyphenol and dissolved in 50 ml. of pentane and 50 ml. benzene. 2 gm of anhydrous ZnCl2 was added and the reaction mixture refluxed for 1 hour and cooled. The mixture was extracted with ether and washed successively with 100 ml. of water, 100 ml. 5% sodium carbonate and 100 ml. of saturated salt solution. After drying the extract over anhydrous sodium sulfate, the solvent was removed in vacuo leaving 7.4 g of crude chromane. The crude material was fractionated on a column of Florisil and eluted with increasing concentrations of ether in petroleum ether to yield 4.5 g of pure chromane.

Workup

  1. dissolutiondissolved in 50 ml
  2. temperaturethe reaction mixture refluxed for 1 hour
  3. temperaturecooled
  4. extractionThe mixture was extracted with ether
  5. washwashed successively with 100 ml
  6. customAfter drying the
  7. extractionextract over anhydrous sodium sulfate
  8. customthe solvent was removed in vacuo

Sources & evidence

ORD record
ord-9e50d23c0af844198d38b5b28b3d9f58
Source dataset
uspto-grants-1987_04
Patent number
US04656189

Reaction notes

Loading…