Thiazole and thiadiazole derivatives, their preparation and pharmaceutical compositions useful in the treatment of throm bocytopenia

摘要

A compound of formula (I) wherein R1 is hydrogen, etc., R2 is N- or S-containing unsaturated heterocyclic group, each of which may have suitable substituent(s), X is CH or N and A is (II) or (III) (wherein m is an integer of 0, 1 or 2) and a pharmaceutically acceptable salt thereof, which is useful as a medicament.