Pyridine → 4-Benzoxazolecarboxylic acid, 2-methyl-, methyl ester

Participants

Reaction Steps

A solution of methyl 2-amino-3-hydroxybenzoate (167 mg, 1.0 mmol), acetyl chloride (86 mg, 1.1 mmol) and triethylamine (101 mg, 1.1 mmol) in xylene (10 mL) was stirred at 0° C. for 2 h. Pyridine (20 mg, 0.25 mmol) and TsOH (43 mg, 0.25 mmol) were then added and the mixture was heated at reflux overnight. The mixture was then cooled to room temperature, diluted with water and extracted with ethyl acetate. The combined organic extracts were washed with water, brine, then dried over sodium sulfate and the solvent was removed under reduced pressure. The residue was purified by flash chromatography using petroleum ether/ethyl acetate 5:1 (v:v) as eluent to give methyl 2-methylbenzo[d]oxazole-4-carboxylate (151 mg, 79%). LC-MS (ES-API); rt 8.08 min; m/z calculated for C10H9NO3 [M+H]+ 192.1, found 192.1.

Provenance & Evidence