| abstract |
Pharmaceutical composition and use for cancer treatment. Claim 1: A compound characterized by the formula (1) in which the ring A is a 5- to 7-membered ring that has an optional substituent (s), wherein the substituents are optionally linked together to form a ring ; X is O, S or NR1 (R1 is a hydrogen atom or a hydrocarbon group which optionally has a substituent (s)); R2 is carbamoyl which optionally has substituent (s); and R3 is hydroxy which has substituent (s) optionally, except the following compounds; of formulas (2) or one of its salts. |