Provided are an industrially useful method for producing a fused-heterocyclic derivative or salt thereof which is useful as a preventive agent, therapeutic agent, reproductive adjustment agent, contraceptive, ovulation-inducing agent, or sex-hormone-dependent-cancer-post-operation-recurrence preventive agent which target sex-hormone-dependent diseases and the like such as prostate enlargement, uterine myoma, endometriosis, uterine fibroma, precocious puberty, amenorrhea, premenstrual syndrome, dysmenorrhea, polycystic ovary syndrome, lupus erythematosus, hypertrichosis, dwarfism, sleep disorders, acne, baldness, Alzheimer's disease, infertility, irritable bowel syndrome, prostate cancer, uterine cancer, ovarian cancer, breast cancer, and pituitary tumors； and a production intermediate thereof. The present invention makes it possible to produce a compound or salt thereof represented by general formula (A) in high yield and purity by using a compound represented by general formula (D) (R1 and R2 represent identical or different C1-6 alkyl groups, and R3 represents a hydrogen atom, a halogen atom, a C1-6 alkyl group, or a nitro group).
