Ethyl orthoformate → 7-Methoxybenzo[d]oxazole

Beteiligte Stoffe

Reaktionsschritte

A mixture of 2-nitro-6-methoxyphenol (2.62 g, 15.5 mmol) (EP 333176) and 10% Palladium on carbon (130 mg) in ethanol (50.0 ml) was stirred under an atmosphere of H2 f or 75 min. The mixture was filtered through Celite® then immediately treated with p-toluenesulphonic acid (32.0 mg) and triethylorthoformate (6.45 ml, 38.8 mmol) then heated under reflux under an atmosphere of N2. After 20 h p-toluenesulphonic acid (30.0 mg) and triethylorthoformate (6.45 ml, 38.8 mmol) were added. After a total of 44 h heating, the reaction was allowed to cool and reduced in vacuo. The resulting residue was purified by flash chromatography (25:75 ethyl acetate/hexane) to give 1.97 g (85%) of the title compound as a yellow solid: m.p. 28-31° C.; IR (film) 1629, 1497, 1434, 1285, 1097;

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