Reaktion #7871

Reaktionsgleichung

trimethylsilyl polyphosphate

2-aminopyridin-3-ol

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

→

2-(3-methoxy-4-pyridin-2-ylphenyl)[1,3]oxazolo[4,5-b]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

Vorschrift

To 5 mL of trimethylsilyl polyphosphate was added 2-aminopyridin-3-ol (175 mg, 1.59 mmol) and 3-methoxy-4-pyridin-2-ylbenzoic acid (344 mg, 1.50 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, and concentrated in vacuo to give 2-(3-methoxy-4-pyridin-2-ylphenyl)[1,3]oxazolo[4,5-b]pyridine as a light yellow solid. 1H NMR (DMSO-d6, 300 MHz) δ 8.72 (d, 1H), 8.58 (d, 1H), 8.30 (d, 1H), 8.05–7.91 (m, 4H), 7.88 (t, 1H), 7.51 (dd, 1H), 7.40 (dd, 1H), 4.02 (s, 3H); MS (ESI) 304 (M+H)+.

Quelle