2-Hydroxy-1-naphthaldehyde → 2-(5-carboxy-2-benzoxazolyl)-3H-naphtho[2,1-b]pyran-3-one

Participants

Reaction Steps

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##

Provenance & Evidence