The present invention provides pyrazine derivatives of formula I and pharmaceutically acceptable salts thereof, wherein the designation of R1, R2, R3 and R4 is provided herein. The invention also provides syntheses for preparation of such compounds. The invention further provides methods of use of these compounds and pharmaceutical compositions containing them for treatment and/or prevention of diseases and for manufacture of medicaments. These compounds and pharmaceutical compositions have antioxidative and thrombolytic effects, and thus can be used for the treatment and/or prevention of cerebral stroke caused by ischemia, and used for manufacture of medicaments for the treatment and/or prevention of nervous system diseases caused by excessive amount of radicals and/or thrombosis, infectious diseases, metabolic system diseases, cardiovascular and cerebrovascular diseases, and age-related degenerative diseases.本発明は下記の一般式(I)で表される一種のピラジン（Pyrazine）誘導体及びその製造方法に関する。該種類化合物は抗酸化と血栓溶解作用を持ち、虚血性脳卒中を治療でき、フリーラジカル(free radicals)過剰および/または血栓形成により起こす神経系疾患、感染症、代謝性疾患、心臓・脳血管疾患及び後退性老化疾患などに対する医薬品の製造に使用できる。
