反应详情

温度

90 °C

A mixture of compound 3 (350 mg, 1.05 mmol) and HMTA (560 mg, 4 mmol) in AcOH (35 mL) was heated to 90° C. under N2 for 1.5 h. The reaction was monitored by LCMS. After cooled to RT, the solvent was removed under vacuum. The residue was purified by prep-HPLC to give 5-hydroxybenzo[d]oxazole-4-carbaldehyde (152 mg, 25% yield). 1HNMR (DMSO, 400 MHz): δ 10.99 (s, 1H, OH), 10.53 (s, 1H, CHO), 8.86 (s, 1H, ArH), 8.00 (d, 1H, J=9.2 Hz, ArH), 7.05 (d, 1H, J=8.8 Hz, ArH). MS [ESI, MH+]: 164.1.

1. temperatureAfter cooled to RT
2. customthe solvent was removed under vacuum
3. customThe residue was purified by prep-HPLC