2H,8H-Benzo(1,2-b:5,4-b')dipyran-3-carboxylic acid, 10-methoxy-2-oxo-, ethyl ester 93669-70-6 Ethyl 10-methoxy-2-oxo-2H,8H-benzo(1,2-b:5,4-b')dipyran-3-carboxylate