Reaktion #7864

Reaktionsgleichung

HCl

trimethylsilyl polyphosphate

2-amino-6-fluorophenol

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

→

7-fluoro-2-(3-methoxy-4-pyridin-2-ylphenyl)-1,3-benzoxazole hydrochloride

Lösungsmittel

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigequenched over ice
2. 2
   ExtraktionThe aqueous phase was extracted with EtOAc (3×150 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
   Sonstigeto give a tan solid
8. 8
   FiltrationThe solution was filtered

Vorschrift

To 7 mL trimethylsilyl polyphosphate was added 2-amino-6-fluorophenol (166 mg, 1.31 mmol) and 3-methoxy-4-pyridin-2-ylbenzoic acid (300 mg, 1.31 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 EtOAc (3×150 mL). The combined organic layers were washed with brine, dried over MgSO4, filtered, and concentrated in vacuo. The resultant oil was taken up in ether and reconcentrated to give a tan solid. The free base was dissolved in ether and HCl (1N in ether) was added. The solution was filtered to give 7-fluoro-2-(3-methoxy-4-pyridin-2-ylphenyl)-1,3-benzoxazole hydrochloride as a yellow solid. 1H NMR (DMSO-d6, 300 MHz) δ 8.71 (d, 1H), 8.00 (t, 1H), 7.97–7.84 (m, 4H), 7.70 (d, 1H), 7.49–7.37 (m, 3H), 4.00 (s, 3H); MS (ESI) 321 (M+H)+.

Quelle