Tetrafluoroboric acid → Methyl 2-chloro-5-fluorobenzoate

HRID 1363409Notes

Reaction equation

HRID 1363409 reaction equation
N([O-])=O.[Na+].N[C:6]1[CH:7]=[CH:8][C:9]([Cl:16])=[C:10]([CH:15]=1)[C:11]([O:13][CH3:14])=[O:12].[F:17][B-](F)(F)F.[H+]>Cl>[CH3:14][O:13][C:11](=[O:12])[C:10]1[CH:15]=[C:6]([F:17])[CH:7]=[CH:8][C:9]=1[Cl:16]

Participants

5

Reactant 3

HCID 28118Tetrafluoroboric acidHCID 5200412Methyl 5-Amino-2-chlorobenzoateHCID 23668193Sodium Nitrite

Product 1

HCID 23331706Methyl 2-chloro-5-fluorobenzoate

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidSolvent

Procedure

A solution of NaNO2 (3.69 g, 53.4 mmol in 50 mL water) was added dropwise to a stirred suspension of methyl 5-amino-2-chlorobenzoate (9 g, 48.5 mmol) in HCl (10%, 90 mL), keeping the temperature between 0-5° C. The reaction mixture was stirred for 10 min. and a solution of fluoroboric acid (70%, excess) was added to the mixture. The precipitate of diazonium fluoroborate salt was filtered, washed with water and dried. The pyrolysis of this salt was then carried out at 140° C. for 15-20 min. The residue was purified using a silica gel column and 10% CHCl3 in petroleum ether (60-80° C.) as an eluant to furnish the title compound.

Workup

  1. custombetween 0-5° C
  2. filtrationThe precipitate of diazonium fluoroborate salt was filtered
  3. washwashed with water
  4. customdried
  5. waitThe pyrolysis of this salt was then carried out at 140° C. for 15-20 min
  6. customThe residue was purified
  7. customa silica gel column and 10% CHCl3 in petroleum ether (60-80° C.)

Sources & evidence

ORD record
ord-ee25cf81698c4952813d2d4ccd996414
Source dataset
uspto-grants-2011_02
Patent number
US07884127B2

Reaction notes

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