New fluorescent compounds, benzo[4,5]thieno[3,2-d]pyrimidine 5,5-dioxides (3a–g), 2-amino-4-methylsulfanylbenzo[4,5]thieno[3,2-d]pyrimidine (6), and 2-amino-4-methylsulfanyl-7-methoxybenzo[4,5]furo[3,2-d]pyrimidine (7), were synthesized in good yields from heterocyclic ketene dithioacetals (1a–c) and guanidine carbonate (2a) or (S)-methylisothiourea sulfate (2b) in pyridine under reflux. Among the fused pyrimidine derivatives, compound 3c, which has an amino group at the 2-position and a benzylamino group at the 4-position of the pyrimidine ring, showed the strongest solid-state fluorescence. The absorption and emission properties of the compounds were quantitatively reproduced by a series of ab initio quantum-chemical calculations.
新的荧光化合物,苯并[4,5]噻吩[3,2-d]嘧啶5,5-二氧化物(3a-g),2-氨基-4-甲基硫醇苯并[4,5]噻吩[3,2-d]嘧啶(6)和2-氨基-4-甲基硫醇-7-甲氧基苯并[4,5]呋喃[3,2-d]嘧啶(7),从杂环酮二硫代乙酸酯(1a-c)和碳酸胍(2a)或(S)-甲基异硫脲硫酸盐(2b)在吡啶中回流合成,并且产率良好。在融合的嘧啶衍生物中,化合物3c,在嘧啶环的2位具有氨基基团,在4位具有苄氨基基团,显示出最强的固态荧光。这些化合物的吸收和发射性质被一系列从头计算的量子化学计算量化地再现。