Hydrogen Bromide → Chroman

HRID 1262573Notes

Reaction equation

HRID 1262573 reaction equation
CO[C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[CH2:9][CH2:10][C:11](C)([OH:19])CC1CCCCN1.Br>C(O)(=O)C>[O:19]1[C:3]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH2:9][CH2:10][CH2:11]1

Participants

4

Reactant 2

HCID 260Hydrogen BromideHCID 20456964HCID 20456964, compound

Product 1

HCID 136319Chroman

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Mother liquors made as in part (a), (24 g) are taken up in 200 ml of glacial acetic acid and treated with 100 ml of 48% HBr. After refluxing for 3 hours under nitrogen the mixture is evaporated to an oil, basified (sodium hydroxide), extracted with chloroform, dried (potassium carbonate) and evaporated to 20 g of oil. This is chromatographed on 200 g of alumina (basic, activity I) in chloroform. Intermediate fractions (500 ml) give 12 g (57%) of single spot oily chroman.

Workup

  1. temperatureAfter refluxing for 3 hours under nitrogen the mixture
  2. customis evaporated to an oil
  3. extractionextracted with chloroform
  4. dry with materialdried (potassium carbonate)
  5. customevaporated to 20 g of oil
  6. customThis is chromatographed on 200 g of alumina (basic, activity I) in chloroform

Sources & evidence

ORD record
ord-1c8f741cd94b4c29b12923d2afa50e78
Source dataset
uspto-grants-1984_06
Patent number
US04452801

Reaction notes

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