1,2-Dibromoethane → 2,2,4-trimethyl-7-(2'-bromo-ethyl-oxy)-(2H)-chromene

HRID 979395

Reaction equation

HRID 979395 reaction equation
[CH3:1][C:2]1([CH3:14])[CH:11]=[C:10]([CH3:12])[C:9]2[C:4](=[CH:5][C:6]([OH:13])=[CH:7][CH:8]=2)[O:3]1.[OH-].[Na+].C1C=CC=CC=1.[Cl-].C([NH+](CCCC)CCCC)CCC.[Br:37][CH2:38][CH2:39]Br>C(Cl)Cl>[CH3:1][C:2]1([CH3:14])[CH:11]=[C:10]([CH3:12])[C:9]2[C:4](=[CH:5][C:6]([O:13][CH2:39][CH2:38][Br:37])=[CH:7][CH:8]=2)[O:3]1

Participants

6

Reactant 4

HCID 78391,2-DibromoethaneHCID 14798Sodium HydroxideHCID 111379242,2,4-trimethyl-2H-chromen-7-olHCID 19833285Benzene tributyl-ammonium-chloride

Product 1

HCID 201999632,2,4-trimethyl-7-(2'-bromo-ethyl-oxy)-(2H)-chromeneYield 65%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a 8% aqueous solution of 0.1 mole (19.02 g.) 2,2,4-trimethyl-7-hydroxy-(2H)-chromene and 0.2 mole (8 g.) sodium hydroxide 4 g. of benzene-tributyl-ammonium-chloride as phase transfer catalyst and a solution of 0.2 mole 1,2-dibromo-ethane in 200 ml. methylene-chloride are added under stirring and the solution is heated for 12 hours. After cooling the organic layer is separated and dried above sodium sulphate and evaporated. The residue is dissolved in 50 ml. diethyl-ether and the substance is precipitated by adding 300 ml. of n-hexane. The solvent is decanted from the precipitated substance. Thus 19.38 g. (0.065 mole) product are obtained in the form of a white waxy oily substance.

Workup

  1. temperaturethe solution is heated for 12 hours
  2. temperatureAfter cooling the organic layer
  3. customis separated
  4. dry with materialdried above sodium sulphate
  5. customevaporated
  6. dissolutionThe residue is dissolved in 50 ml
  7. customdiethyl-ether and the substance is precipitated
  8. additionby adding 300 ml
  9. customThe solvent is decanted from the precipitated substance

Sources & evidence

ORD record
ord-4169638a2260490ea0bb37594a12537a
Source dataset
uspto-grants-1987_05
Patent number
US04668274

Linked notes

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