| abstract |
PROBLEM TO BE SOLVED: To provide a drug effective for prevention or treatment of autism spectrum disorder. SOLUTION: A compound of formula (I) having a melatonin receptor affinity or a salt thereof. In the formula, X is O or S, m is 0 to 2, R 1 is a hydrocarbon group which may have a substituent, amino, hydroxy or heterocyclic group, and R 5 is H. , Halogen, a hydrocarbon group which may have a substituent, amino, hydroxy or mercapto, R 6 indicates an H or a hydrocarbon group which may have a substituent, rings A, B, C may have a substituent. [Selection diagram] Fig. 1 |