1,2-Dichloroethane → 2H-1-Benzopyran-2-one, 7-(2-bromoethoxy)-4-methyl-

HRID 979396Notes

Reaction equation

HRID 979396 reaction equation
[OH:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6]([CH3:13])=[CH:7][C:8](=[O:12])[O:9]2)=[CH:4][CH:3]=1.[OH-].[Na+].[Br:16][CH2:17][CH2:18]Br.C(Cl)CCl>[Cl-].C([N+](CCCC)(CCCC)CCCC)C1C=CC=CC=1.ClCCl>[Br:16][CH2:17][CH2:18][O:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6]([CH3:13])=[CH:7][C:8](=[O:12])[O:9]2)=[CH:4][CH:3]=1

Participants

7

Reactant 4

HCID 111,2-DichloroethaneHCID 78391,2-DibromoethaneHCID 14798Sodium HydroxideHCID 52805674-Methylumbelliferone

Product 1

HCID 3444002H-1-Benzopyran-2-one, 7-(2-bromoethoxy)-4-methyl-Yield 70%

Reagents, catalysts & solvents 2

HCID 159952Benzyltributylammonium chlorideCatalystHCID 6344DichloromethaneSolvent

Procedure

17.62 g. (0.1 mole) 7-hydroxy-4-methyl-coumarin (4-methyl-umbelliferon) are dissolved in a 8% aqueous solution of 0.2 mole sodium hydroxide and a solution of 4 g. benzyl-tributyl-ammonium-chloride phase transfer catalyst and 37.5 g. (0.2 mole) 1,2-dibromo-ethane in 200 ml. ethylene-chloride is added. The mixture is heated for 14 hours under stirring and allowed to cool. 60 ml. dichloromethane are added, the mixture is filtered and the organic layer is separated from the filtrate and washed with distilled water, dried and evaporated. 19.82 g. (0.07 mole) 7-(2'-bromo-ethyl-oxy)-4-methyl-coumarin are obtained, melting point: 94°-97° C.

Workup

  1. temperatureThe mixture is heated for 14 hours
  2. temperatureto cool
  3. filtrationthe mixture is filtered
  4. customthe organic layer is separated from the filtrate
  5. washwashed with distilled water
  6. customdried
  7. customevaporated

Sources & evidence

ORD record
ord-d8337c7d86f94438bd5eec236a7d1c73
Source dataset
uspto-grants-1987_05
Patent number
US04668274

Reaction notes

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