A process for producing a dicarboxylic acid compound represented by the formula (4): wherein R1 and R2 are the same or different and each represents lower alkyl and the wavy line indicates that this compound is the E- or Z-isomer or a mixture of them, characterized by reacting a compound represented by the formula (2): wherein R1, R2 and the wavy line have the same meanings as the above, and one of X2 and X3 represents hydrogen and the other represents halogen, with nitrophenol represented by the formula (3): in the presence of a base; a process for producing a nitrochromone compound represented by the formula (5): wherein R1 has the same meaning as the above, characterized by reacting the dicarboxylic acid compound or carboxylic acid thereof with an acid; a process for producing an aminochromone compound which comprises reducing the nitrochromone compound; and a process for producing an amidochromone compound which comprises acylating the aminochromone compound are provided.