Bromine → Ethyl 8-bromo-6-chloro-7-hydroxychroman-4-carboxylate

HRID 1048032Notes

Reaction equation

HRID 1048032 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][C:11]=1[OH:12])[O:8][CH2:7][CH2:6][CH:5]2[C:13]([O:15][CH2:16][CH3:17])=[O:14].[Br:18]Br>C(O)(=O)C>[Br:18][C:10]1[C:11]([OH:12])=[C:2]([Cl:1])[CH:3]=[C:4]2[C:9]=1[O:8][CH2:7][CH2:6][CH:5]2[C:13]([O:15][CH2:16][CH3:17])=[O:14]

Participants

4

Reactant 2

HCID 24408Bromine2×HCID 53393319Ethyl-6-chloro-7-hydroxy-3,4-dihydro-2H-chromene-4-carboxylate

Product 1

HCID 67080498Ethyl 8-bromo-6-chloro-7-hydroxychroman-4-carboxylateYield 90.1%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To a stirred solution of ethyl 6-chloro-7-hydroxychroman-4-carboxylate (5.14 g, 20.0 mmol) in glacial acetic acid (50 mL) at ambient temperature was added bromine (1.2 mL, 24 mmol), in six equal portions, waiting 30-60 seconds between each addition for the bromine color to be discharged. Following completion of addition, the solution was concentrated and the residue concentrated from toluene, then partitioned between ethyl acetate (200 mL) and 5% sodium bisulfite (100 mL). The organic was layer dried over sodium sulfate, then stirred with activated charcoal (2 g) at ambient temperature for 20 minutes. The charcoal was removed by filtration through a glass microfibre filter and the filtrate was concentrated to afford ethyl 8-bromo-6-chloro-7-hydroxychroman-4-carboxylate as a light brown oil (6.05 g, 90% yield).

Workup

  1. additioncompletion of addition
  2. concentrationthe solution was concentrated
  3. concentrationthe residue concentrated from toluene
  4. custompartitioned between ethyl acetate (200 mL) and 5% sodium bisulfite (100 mL)
  5. dry with materialdried over sodium sulfate
  6. customThe charcoal was removed by filtration through a glass microfibre
  7. filtrationfilter
  8. concentrationthe filtrate was concentrated

Sources & evidence

ORD record
ord-050b21bc34f54e0ba2d4254e9ee73257
Source dataset
uspto-grants-2013_10
Patent number
US08569522B2

Reaction notes

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