| abstract |
The present invention provides a preventive or therapeutic agent for pulmonary hypertension, including a compound represented by the following formula (I) or a salt thereof: where: —A— represents —NH—, —S—, or —O—; R 1 and R 2 are identical to or different from each other, and each represent a hydrogen atom or an alkyl group; R 3 represents a hydrogen atom, a halogen atom, or an alkyl group; R 4 represents a hydrogen atom or an alkyl group; R 5 represents a hydrogen atom or an alkyl group; R 6 and R 7 are identical to or different each other, and each represent a hydrogen atom, a halogen atom, or an alkyl group; and R 6 and R 7 may form an unsaturated hydrocarbon six-membered ring together with a carbon atom to which R 6 is bonded and a carbon atom to which R 7 is bonded. |