反应详情

4-Nitrobenzaldehyde (4.5 g, 29.7 mmol) and then a number of drops of piperidine were added to a benzene (40 ml) solution of dehydroacetic acid (5.00 g, 29.7 mmol) at room temperature, after which refluxing was performed for 6 hours while eliminating water by azeotropy. The majority of the benzene was distilled of directly, and then the distillation taken to dryness under reduced pressure. Following which, when recrystallization was performed from ethanol, 4-hydroxy-6-methyl-3-(4-nitrophenyl)acryloyl-2-pyrone (7.3 g, 82%) was obtained as orange crystals.

1. temperatureafter which refluxing
2. distillationThe majority of the benzene was distilled of directly, and then
3. distillationthe distillation
4. customwhich, when recrystallization