Boron tribromide → HCID 14254546, compound

HRID 1905086Notes

Reaction equation

HRID 1905086 reaction equation
[Cl:1][C:2]1[C:7]2[C:8](=[O:19])[C:9]([C:12]3[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=3[OH:18])=[CH:10][O:11][C:6]=2[CH:5]=[C:4]([O:20][CH2:21][C:22]([O:24]CC)=[O:23])[CH:3]=1.C(=O)=O.CC(C)=O.B(Br)(Br)Br>ClCCl>[Cl:1][C:2]1[C:7]2[C:8](=[O:19])[C:9]([C:12]3[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=3[OH:18])=[CH:10][O:11][C:6]=2[CH:5]=[C:4]([O:20][CH2:21][C:22]([OH:24])=[O:23])[CH:3]=1

Participants

5

Reactant 3

HCID 25134Boron tribromideHCID 14254511HCID 14254511, compoundHCID 18522661Acetone cardice

Product 1

HCID 14254546HCID 14254546, compoundYield 63.6%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

In 100 ml of dried dichloromethane was dissolved 1.7 g of ethyl {[5-chloro-3-(2-hydroxyphenyl)-4-oxo-4H-1-benzopyran-7-yl]oxy}acetate, and the solution was cooled with dry ice-acetone. Three milliliters of boron tribromide were added to the cooled solution in small portions, and the resulting mixture was refluxed for 3 hours. After cooling, the solvent was removed by distillation under reduced pressure, and to the residue was added dilute hydrochloric acid. The precipitated crystals were collected by filtration, washed with water, air-dried, and recrystallized from ethanol to obtain 1.0 g of the entitled compound having a melting point of 188°-189° C. (with decomposition).

Workup

  1. temperaturethe resulting mixture was refluxed for 3 hours
  2. temperatureAfter cooling
  3. customthe solvent was removed by distillation under reduced pressure
  4. additionto the residue was added dilute hydrochloric acid
  5. filtrationThe precipitated crystals were collected by filtration
  6. washwashed with water
  7. customair-dried
  8. customrecrystallized from ethanol

Sources & evidence

ORD record
ord-e6192c3dd46d4e0b8413e91e1a393941
Source dataset
uspto-grants-1989_06
Patent number
US04841076

Reaction notes

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