142689-07-4 3H-2-Benzopyran-7-carboxylic acid, 4,6-dihydro-5-bromo-3,4-dimethyl-8-hydroxy-6-oxo- 4,6-Dihydro-5-bromo-3,4-dimethyl-8-hydroxy-6-oxo-3H-2-benzopyran-7-carboxylic acid