Novel tricyclic fused pyrimidine derivatives of the formula (I):
 wherein either one of R¹ and R² is hydrogen or an optionally substituted aralkyl group and the other is hydrogen, an optionally substituted aralkyl group or an aliphatic hydrocarbon group; R³ is hydrogen, an aliphatic hydrocarbon group or acyl group; and A is an optionally substituted divalent hydrocarbon chain having 2 to 4 carbon atoms and salts thereof are strong adenosine antagonists and activate cerebral functions and metabolisms, thus being useful as therapeutic or prophylactic agents for neurological or psychic changes caused by cerebral apoplexy, brain injury or cerebral atrophy.  
                            式(I)的新型
三环融合
嘧啶衍
生物:
 其中 R¹ 和 R² 中的一个是氢或任选取代的芳烷基,另一个是氢、任选取代的芳烷基或脂族烃基;R³ 是氢、脂族烃基或酰基;和 A 是具有 2 至 4 个碳原子的任选取代的二价烃链,其盐类是强效的
腺苷拮抗剂,可激活脑功能和新陈代谢,因此可用作治疗或预防脑中风、脑损伤或脑萎缩引起的神经或精神变化的药物。