Phosphorus oxychloride → 2-(3-Bromophenyl)-4-(chloromethyl)-5-methyl-1,3-oxazole

HRID 2417032Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 2417032
[Br:1][C:2]1[CH:3]=[C:4]([C:8]2[O:9][C:10]([CH3:15])=[C:11]([CH3:14])[N+:12]=2[O-])[CH:5]=[CH:6][CH:7]=1.P(Cl)(Cl)([Cl:18])=O>C(Cl)(Cl)Cl>[Br:1][C:2]1[CH:3]=[C:4]([C:8]2[O:9][C:10]([CH3:15])=[C:11]([CH2:14][Cl:18])[N:12]=2)[CH:5]=[CH:6][CH:7]=1

Komponenten

4

Edukt 2

HCID 24813Phosphorus oxychlorideHCID 40877752-(3-Bromophenyl)-4,5-dimethyloxazole-3-oxide

Produkt 1

HCID 40879032-(3-Bromophenyl)-4-(chloromethyl)-5-methyl-1,3-oxazoleAusbeute 72 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6212ChloroformLösungsmittel

Versuchsvorschrift

A solution of 2-(3-bromophenyl)-4,5-dimethyloxazole-3-oxide (96.6 g, 0.36 mol) in CHCl3 (0.90 L) was treated dropwise with phosphorous oxychloride (61.1 g, 0.40 mol) allowing the reaction to exotherm and then stirred at reflux for 30 min. The reaction was then cooled to room temperature and washed with water (2×1 L). The combined aqueous washes were back extracted with CH2Cl2 (2×400 mL). The organic layers were dried (MgSO4), and the solvent removed in vacuo to give crude product that was recrystallized from hot hexanes (300 mL), decanting the hot supernate away from a dark oily material. The remaining dark oil was agitated in additional hot hexanes (200 mL) and the combined supernates were cooled to 0° C. to crystallize the product which was isolated by filtration to give 74.2 g (72%) of 2-(3-bromophenyl)-4-(chloromethyl)-5-methyloxazole as a lime-green powder. 1H NMR (300 MHz, d6-DMSO) δ 8.19 (s, 1H), 7.93 (d, J=8.0 Hz, 1H), 7.58 (d, J=8.0 Hz, 1H), 7.35 (t, J=8.0 Hz, 1H), 4.45 (s, 2H), 2.41 (s, 3H).

Aufarbeitung

  1. customthe reaction
  2. temperatureat reflux for 30 min
  3. washwashed with water (2×1 L)
  4. extractionThe combined aqueous washes were back extracted with CH2Cl2 (2×400 mL)
  5. dry with materialThe organic layers were dried (MgSO4)
  6. customthe solvent removed in vacuo
  7. customto give crude product that
  8. customwas recrystallized from hot hexanes (300 mL)
  9. customdecanting the hot supernate away from a dark oily material
  10. stirringThe remaining dark oil was agitated in additional hot hexanes (200 mL)
  11. temperaturethe combined supernates were cooled to 0° C.
  12. customto crystallize the product which
  13. customwas isolated by filtration

Quellen und Nachweise

ORD-Eintrag
ord-e22322bfb1534465909dae9f721b5db7
Quelldatensatz
uspto-grants-2004_11
Patentnummer
US06825222B2

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