20110009415Thienopyridazine Compounds, Their Preparations, Pharmaceutical Compositions And Uses - The present invention relates to thienopyridazine compounds of formula (I), their pharmaceutically acceptable salts or hydrates, wherein R1 and R2 are independently H or C1-4 alkyl, R3 is a saturated or unsaturated 5- or 6-membered ring containing N, S or O, or its optical isomers, R4 is a halophenyl