title: Synthesis, solid-state fluorescence properties, and computational analysis of novel 2-aminobenzo[4,5]thieno[3,2-d]pyrimidine 5,5-dioxides.
abstract: 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.
authors.affiliation: Faculty of Environmental Studies, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan.
authors.forename: Kenichirou
authors.initials: K
authors.lastname: Yokota
authors.forename: Masayori
authors.initials: M
authors.lastname: Hagimori
authors.forename: Naoko
authors.initials: N
authors.lastname: Mizuyama
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Nishimura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujito
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shigemitsu
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Tominaga