Hydrochloric Acid → 2-Chloro-4-fluorobenzeneboronic acid

HRID 1764902Notes

Reaction equation

HRID 1764902 reaction equation
C([Li])CCC.[Cl:6][C:7]1[CH:12]=[C:11]([F:13])[CH:10]=[CH:9][C:8]=1I.C[O:16][B:17](OC)[O:18]C.Cl>C1COCC1>[Cl:6][C:7]1[CH:12]=[C:11]([F:13])[CH:10]=[CH:9][C:8]=1[B:17]([OH:18])[OH:16]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 8470Trimethyl borateHCID 27365592-Chloro-4-fluoro-1-iodobenzeneHCID 178418339Butyllithium

Product 1

HCID 177502292-Chloro-4-fluorobenzeneboronic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

n-Butyllithium (1.6 M solution in hexanes, 23.5 mmol, 14.7 mL) was added to 2-chloro-4-fluoro-1-iodobenzene (19.6 mmol, 5.0 g) in THF (120 mL) at −78° C. under an atmosphere of nitrogen. After stirring for thirty minutes the trimethylborate (76.6 mmol, 8.7 mL) was added over twenty minutes. The reaction was allowed to warm to room temperature overnight while stirring. The solution was then acidified with HCl (3 M, 200 mL), and extracted into EtOAc. The EtOAc was then extracted with NaOH (1 N, 4×100 mL), which was subsequently acidified with concentrated HCl forming (2-chloro-4-fluorophenyl)boronic acid as a white precipitate. The white precipitate (1.10 g, 33%) was filtered and dried. 1H NMR (CDCl3, 300 MHz): 7.96 (1H, t, J 8.1 Hz), 7.11 (1H, dd, J 8.8 and 2.5 Hz), 7.04 (1H, td, J 8.4 and 2.5 Hz), 5.28 (2H, s.)

Workup

  1. additionwas added over twenty minutes
  2. extractionextracted into EtOAc
  3. extractionThe EtOAc was then extracted with NaOH (1 N, 4×100 mL), which

Sources & evidence

ORD record
ord-5e7945ce6f4946c3b3573d1ccbc3e038
Source dataset
uspto-grants-2007_06
Patent number
USRE039679E1

Reaction notes

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