2-Bromo- (II) and 2,2-dibromo-1,3-indandione (III) react with pyridine, 3- and 4-methylpyridine, and 2-, 3-, and 4-pyridinecarboxylic acids to give 1-(3-hydroxy-1-oxo-2-indenyl)-pyridinium hydroxide betaines. In the betaines derived from pyridinecarboxylic acids the negative charge is located not in the carboxylic group but on the carbonyl oxygen atoms.