Hydrochloric Acid → (2-Chloro-4-isopropoxyphenyl)boronic acid

HRID 1764900Notes

Reaction equation

HRID 1764900 reaction equation
C([Li])CCC.Br[C:7]1[CH:12]=[CH:11][C:10]([O:13][CH:14]([CH3:16])[CH3:15])=[CH:9][C:8]=1[Cl:17].C[O:19][B:20](OC)[O:21]C.Cl>C1COCC1>[Cl:17][C:8]1[CH:9]=[C:10]([O:13][CH:14]([CH3:16])[CH3:15])[CH:11]=[CH:12][C:7]=1[B:20]([OH:21])[OH:19]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 8470Trimethyl borateHCID 227354041-Bromo-2-chloro-4-isopropoxybenzeneHCID 178418339Butyllithium

Product 1

HCID 22735874(2-Chloro-4-isopropoxyphenyl)boronic acidYield 44%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

n-Butyllithium (1.6 M solution in hexanes, 23.5 mmol, 14.7 mL) was added to 1-bromo-2-chloro-4-isopropoxybenzene (19.4 mmol, 4.85 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-isopropoxyphenyl)boronic acid (1.82 g, 44%) as a white precipitate, which was filtered and dried. 1H NMR (CD3OD, 300 MHz): 7.19 (1H, d, J 8.4 Hz), 6.87 (1H, d, J 2.2 Hz), 6.82 (1H, dd, J 8.4 and 2.2 Hz), 4.58 (1H, m), 1.28 (6H, d, J 5.9 Hz.)

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-83d4e4fa16294488b30f723bfae74c15
Source dataset
uspto-grants-2007_06
Patent number
USRE039679E1

Reaction notes

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