反应详情

温度

-30 °C

A mixture of 5.00 g (21 mmol) of 4-dibutylaminobenzaldehyde, 4.27 g (24 mmol) of 4-nitrophenylacetic acid, 1.80 g (21 mmol) of piperidine, and 50 mL of xylenes was heated with stirring at reflux of 20 hours with continuous removal of water using a Dean-Stark apparatus. The mixture turned dark red. Approximately half the xylenes was distilled, 20 mL of heptane was added, and the residue was cooled to -30° C. Red crystals separated which were collected and then recrystallized from toluene/heptane. Yield: 2.81 g (37%), mp 117-119 (lit2 182°-182.5° C.).

1. temperaturewas heated
2. distillationApproximately half the xylenes was distilled
3. addition20 mL of heptane was added
4. customRed crystals separated which
5. customwere collected
6. customrecrystallized from toluene/heptane
7. customYield: 2.81 g (37%), mp 117-119 (lit2 182°-182.5° C.)