Synthesis, solid-state fluorescence properties, and computational analysis of novel 2-aminobenzo[4,5]thieno[3,2-d]pyrimidine 5,5-dioxides.

Kenichirou Yokota,Naoko Mizuyama,Yoshinori Tominaga,Yasuhiro Shigemitsu,Hiroshi Fujito,Masayori Hagimori,Yasuhisa Nishimura

doi:10.3762/bjoc.8.28

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.

Highlights

Solid-state fluorescent compounds are currently attracting considerable interest from both theoretical and practical standpoints [1,2,3,4]
The one-pot synthesis of a new, fluorescent, fused pyrimidine derivative 2,4-diaminoindeno[1,2-d]pyrimidin-5-one; this pyrimidine derivative, which was synthesized by heating a ketene dithioacetal, 2-[bis(methylsulfanyl)methylidene]indan1,3-dione, under reflux with amine and amidine derivatives in pyridine solution, showed blue-green fluorescence in the solid state [6]
We report the synthesis of new fluorescent 2-aminobenzo[4,5]thieno[3,2-d]pyrimidine 5,5-dioxides and related fused pyrimidine derivatives

Summary

Introduction

Solid-state fluorescent compounds are currently attracting considerable interest from both theoretical and practical standpoints [1,2,3,4]. We prepared new pyrimidine derivatives, which have solid-state blue fluorescence, by means of a one-pot synthesis, involving the reaction of ketene dithioacetals, amines, and guanidine carbonate in pyridine [5]. The one-pot synthesis of a new, fluorescent, fused pyrimidine derivative 2,4-diaminoindeno[1,2-d]pyrimidin-5-one; this pyrimidine derivative, which was synthesized by heating a ketene dithioacetal, 2-[bis(methylsulfanyl)methylidene]indan1,3-dione, under reflux with amine and amidine derivatives in pyridine solution, showed blue-green fluorescence in the solid state [6]. These one-pot synthetic methods are promising for the preparation of other new solid-state fluorescent pyrimidine derivatives containing polycyclic heterocycles. The electronic and emission spectra of these new compounds were analyzed computationally by using a series of ab initio quantum-chemical calculations

Methods

Results

Conclusion