Boron tribromide → HCID 69517568, compound

HRID 854896Notes

Reaction equation

HRID 854896 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([O:21]C)[CH:5]=[C:6]2[C:11]=1[O:10][CH:9]([C:12]([F:15])([F:14])[F:13])[C:8]([C:16]([O:18][CH2:19][CH3:20])=[O:17])=[CH:7]2.B(Br)(Br)Br>C(Cl)Cl>[Cl:1][C:2]1[CH:3]=[C:4]([OH:21])[CH:5]=[C:6]2[C:11]=1[O:10][CH:9]([C:12]([F:15])([F:14])[F:13])[C:8]([C:16]([O:18][CH2:19][CH3:20])=[O:17])=[CH:7]2

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 69517224HCID 69517224, compound

Product 1

HCID 69517568HCID 69517568, compoundYield 82%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
-78 °C

Procedure

A solution of ethyl 8-chloro-6-methoxy-2-(trifluoromethyl)-2H-chromene-3-carboxylate prepared as in Step 2 (1.41 g, 4.19 mmole) in anhydrous CH2Cl2 (80 mL) was cooled to −78° C. and a solution of BBr3 in CH2C2 (42 mL-1.0 M, 42.0 mmole) was added dropwise under a dry N2 atmosphere. The dry ice bath was removed and the mixture was allowed to warm to room temperature. After 3 h, the mixture was cooled to −78° C. and quenched by the addition of anhydrous MeOH (20 mL). The solvent was removed in vacuo and the residue extracted with EtOAc (200 mL). The extract was washed with brine, dried over MgSO4, filtered and concentrated in vacuo to give a light brown solid. Purification by silica chromatography (98:2 CH2Cl2—MeOH gave 1.10 g (82% yield) of the product a as dark yellow solid: EIHRMS m/z 322.0215 (M+, C13Hn10ClF3O4, Calc'd 322.0220). 1H NMR (dmso-d6/300 MHz) 9.79 (s, 1H), 7.89 (s, 1H), 6.78-6.91 (m, 2H), 5.99 (q, 1H, J=7.3 Hz), 4.17-4.32 (m, 2H), 1.26 (t, 3H, J=7.05 Hz);

Workup

  1. customThe dry ice bath was removed
  2. temperatureto warm to room temperature
  3. temperaturethe mixture was cooled to −78° C.
  4. customquenched by the addition of anhydrous MeOH (20 mL)
  5. customThe solvent was removed in vacuo
  6. extractionthe residue extracted with EtOAc (200 mL)
  7. washThe extract was washed with brine
  8. dry with materialdried over MgSO4
  9. filtrationfiltered
  10. concentrationconcentrated in vacuo
  11. customto give a light brown solid
  12. customPurification by silica chromatography (98:2 CH2Cl2—MeOH

Sources & evidence

ORD record
ord-b1e176def215471397e412fe5ec9dfdb
Source dataset
uspto-grants-2007_08
Patent number
US07259266B2

Reaction notes

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