反应详情

A mixture of 2-hydroxy-1-naphthaldehyde (1.72 g, 0.01 mol), 2-ethoxycarbonylmethyl-5-carboxybenzoxazole (2.49 g, 0.01 mol), ethanol (30 mL), piperidine (10 drops), and acetic acid (5 drops) is heated at reflux for 3 hours. After cooling the reaction mixture is filtered to isolate the yellow fluorescent product which is then washed with ethanol and dried in air to yield 2.0 g (56% of theory) of 2-(5-carboxy-2-benzoxazolyl)-3H-naphtho[2,1-b]pyran-3-one having the structure ##STR19##

1. temperatureis heated
2. temperatureat reflux for 3 hours
3. temperatureAfter cooling the reaction mixture
4. filtrationis filtered
5. customto isolate the yellow fluorescent product which
6. washis then washed with ethanol
7. customdried in air