Hydrochloric Acid → 2-Chloro-4-ethoxyphenylboronic Acid (contains varying amounts of Anhydride)

HRID 1764898Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1764898
C([Li])CCC.Br[C:7]1[CH:12]=[CH:11][C:10]([O:13][CH2:14][CH3:15])=[CH:9][C:8]=1[Cl:16].C[O:18][B:19](OC)[O:20]C.Cl>C1COCC1>[Cl:16][C:8]1[CH:9]=[C:10]([O:13][CH2:14][CH3:15])[CH:11]=[CH:12][C:7]=1[B:19]([OH:20])[OH:18]

Komponenten

6

Edukt 4

HCID 313Hydrochloric AcidHCID 8470Trimethyl borateHCID 227356231-Bromo-2-chloro-4-ethoxybenzeneHCID 178418339Butyllithium

Produkt 1

HCID 35397162-Chloro-4-ethoxyphenylboronic Acid (contains varying amounts of Anhydride)

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel

Versuchsvorschrift

n-Butyllithium (1.6 M solution in hexanes, 23.5 mmol, 14.7 mL) was added to 1-bromo-2-chloro-4-ethoxybenzene (19.5 mmol, 4.59 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 a white precipitate. The white precipitate (2.25 g, 58%) was filtered and dried to afford (2-Chloro-4-ethoxyphenyl)boronic acid. 1H NMR (CDCl3, 300 MHz): 7.87 (1H, d, J8.4 Hz), 6.88 (1H, d, J 2.5 Hz), 6.84 (1H, dd, J 8.4 and 2.5 Hz), 5.53 (2H, br. s), 4.06 (2H, q, J 7.07 Hz), 1.42 (3H, t, J 7.0 Hz.)

Aufarbeitung

  1. additionwas added over twenty minutes
  2. extractionextracted into EtOAc
  3. extractionThe EtOAc was then extracted with NaOH (1 N, 4×100 mL), which
  4. filtrationThe white precipitate (2.25 g, 58%) was filtered
  5. customdried

Quellen und Nachweise

ORD-Eintrag
ord-5e6cf159072c402d932adc6cd711ccc6
Quelldatensatz
uspto-grants-2007_06
Patentnummer
USRE039679E1

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