Reaktion #483584

Reaktionsgleichung

Triethylamine

2,4-diphenyl-oxazole-5-carboxylic acid

carbonyldiimidazole

→

title compound

Ausbeute 75.0%

2,4-Diphenyl-oxazole-5-carboxylic Acid Methoxy-methyl-amide

Ausbeute 75.0%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture heated at 50° C. for 3 hours
2. 2
   SonstigeThe mixture was partitioned between ethyl acetate and water
3. 3
   WaschenThe organic phase was washed with 5% KHSO4 and brine
4. 4
   Trocknendried over anhydrous sodium sulfate
5. 5
   Einengenconcentrated in vacuo to a brown oil
6. 6
   SonstigeThe crude oil was chromatographed on silica gel eluting with (7:3) hexanes-ether

Vorschrift

A solution of the above-prepared 2,4-diphenyl-oxazole-5-carboxylic acid (427 mg, 1.61 mmole, 1.0 eq) in dry THF was treated with carbonyldiimidazole (340 mg, 2.09 mmole, 1.3 eq) and the mixture heated at 50° C. for 3 hours. Triethylamine (360 uL, 2.58 mmole, 1.6 eq) and N, O-dimethylhydroxylamine-HCl (236 mg, 2.42 mmole, 1.5 eq) were added and the mixture heated at 50° C. for 3 hours. The mixture was partitioned between ethyl acetate and water. The organic phase was washed with 5% KHSO4 and brine, dried over anhydrous sodium sulfate and concentrated in vacuo to a brown oil. The crude oil was chromatographed on silica gel eluting with (7:3) hexanes-ether to give 371 mg (75%) of the title compound as a brown crystalline solid. 1H NMR (CDCl3) δ 3.35 (s, 3H), 3.8 (s, 3H), 7.3-7.6 (m, 6H), 7.95 (dd, 2H), 8.15 (dd, 2H).

Quelle