Chlorotrimethylsilane → 2-[3-Methoxy-4-(pyridin-2-ylmethyl)phenyl]-1,3-benzoxazole

HRID 7750

Reaktionsgleichung

Reaktionsgleichung von HRID 7750
Br[CH2:2][C:3]1[CH:8]=[CH:7][C:6]([C:9]2[O:10][C:11]3[CH:17]=[CH:16][CH:15]=[CH:14][C:12]=3[N:13]=2)=[CH:5][C:4]=1[O:18][CH3:19].Cl[Si](C)(C)C.BrCCBr.Br[C:30]1[CH:35]=[CH:34][CH:33]=[CH:32][N:31]=1>[Zn].C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.C1COCC1>[CH3:19][O:18][C:4]1[CH:5]=[C:6]([C:9]2[O:10][C:11]3[CH:17]=[CH:16][CH:15]=[CH:14][C:12]=3[N:13]=2)[CH:7]=[CH:8][C:3]=1[CH2:2][C:30]1[CH:35]=[CH:34][CH:33]=[CH:32][N:31]=1

Komponenten

8

Edukt 4

HCID 6397ChlorotrimethylsilaneHCID 78391,2-DibromoethaneHCID 79732-BromopyridineHCID 219909912-[4-(Bromomethyl)-3-methoxyphenyl]-1,3-benzoxazole

Produkt 1

HCID 102150812-[3-Methoxy-4-(pyridin-2-ylmethyl)phenyl]-1,3-benzoxazole

Reagenzien, Katalysatoren, Lösungsmittel 3

HCID 23994ZincKatalysatorHCID 178418397HCID 178418397, VerbindungKatalysatorHCID 8028TetrahydrofuranLösungsmittel

Versuchsvorschrift

A solution of 2-[4-(bromomethyl)-3-methoxyphenyl]-1,3-benzoxazole (320 mg, 1.0 mmol) and THF (10 mL) was treated with Zn powder (activated by grinding with mortar and pestle), a drop of chlorotrimethylsilane, and a drop of 1,2-dibromoethane. The mixture was heated at reflux for 1 h. The resultant organozinc reagent was filtered through a plug of Celite, and transferred to a flask containing 2-bromopyridine (360 mg, 2.0 mmol) and Pd(Ph3P)4 (115 mg, 0.1 mmol). The mixture was degassed with bubbling argon for 15 min, and heated at reflux for 12 h. The reaction was poured into H2O (40 mL) and extracted with CH2Cl2 (2×30 mL). The organic extracts were dried (MgSO4) and concentrated to afford a colorless solid. Purification of the solid by flash chromatography on silica gel (EtOAc:hexanes 3:1) afforded the desired 2-[3-methoxy-4-(pyridin-2-ylmethyl)phenyl]-1,3-benzoxazole as a yellow solid: 1H NMR (CDCl3, 300 MHz) δ 8.55 (d, 1H), 7.76–7.82 (m, 3H), 7.56–7.62 (d, 2H), 7.32–7.36 (m, 3H), 7.11–7.16 (m, 2H), 4.23 (s, 2H), 3.95 (s, 3H). MS (ESI) 317 (M+H)+.

Aufarbeitung

  1. temperatureThe mixture was heated
  2. temperatureat reflux for 1 h
  3. filtrationThe resultant organozinc reagent was filtered through a plug of Celite
  4. customtransferred to a flask
  5. customThe mixture was degassed with bubbling argon for 15 min
  6. temperatureheated
  7. temperatureat reflux for 12 h
  8. additionThe reaction was poured into H2O (40 mL)
  9. extractionextracted with CH2Cl2 (2×30 mL)
  10. dry with materialThe organic extracts were dried (MgSO4)
  11. concentrationconcentrated
  12. customto afford a colorless solid
  13. customPurification of the solid by flash chromatography on silica gel (EtOAc:hexanes 3:1)

Quellen und Nachweise

ORD-Eintrag
ord-630d9631f495463896aebb68080e674b
Quelldatensatz
uspto-grants-2006_08
Patentnummer
US07087601B2

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