A process for producing a dicarboxylic acid compound represented by the formula (4): (4) (wherein R<1> and R<2> 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 both), characterized by reacting a compound represented by the formula (2): (2) (wherein R<1>, R<2>, and the wavy line have the same meanings as the above; and one of X<2> and X<3> represents hydrogen and the other represents halogeno) with a nitrophenol represented by the formula (3): (3) in the presence of a base; a process for producing a nitrochromone compound represented by the formula (5): (5) (wherein R<1> has the same meaning as the above), characterized by reacting the dicarboxylic acid compound or a 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.
