Reaktion #7874

Reaktionsgleichung

trimethylsilyl polyphosphate

3-aminopyridin-4-ol

3-methoxy-4-pyridin-2-ylbenzoic acid

→

2-(3-Methoxy-4-pyridin-2-ylphenyl)[1,3]oxazolo[4,5-c]pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigequenched over ice
2. 2
   ExtraktionThe aqueous phase was extracted with MTBE (3×200 mL)
3. 3
   WaschenThe combined organic layers were washed with brine
4. 4
   Trocknendried over MgSO4
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated in vacuo
7. 7
   Sonstigepurified by column chromatography (50–100% EtOAc/hexanes followed by 10% MeOH/CHCl3)

Vorschrift

To 7 mL trimethylsilyl polyphosphate was added 3-aminopyridin-4-ol (330 mg, 3.00 mmol) and 3-methoxy-4-pyridin-2-ylbenzoic acid (460 mg, 2.00 mmol). The mixture was heated at 200° C. for 2 h, quenched over ice, and made basic (pH 14) with 1N NaOH. The aqueous phase was extracted with MTBE (3×200 mL). The combined organic layers were washed with brine, dried over MgSO4, filtered, concentrated in vacuo, and purified by column chromatography (50–100% EtOAc/hexanes followed by 10% MeOH/CHCl3) to give 2-(3-Methoxy-4-pyridin-2-ylphenyl)[1,3]oxazolo[4,5-c]pyridine as a yellow solid. 1H NMR (DMSO-d6, 300 MHz) δ 9.16 (s, 1H), 8.71 (d, 1H), 8.62 (d, 1H), 8.03–7.84 (m, 6H), 7.39 (t, 1H), 4.00 (s, 3H); MS (ESI) 304 (M+H)+.

Quelle