유기발광다이오드를 위한 카바졸 유도체의 효율적인 합성

Abstract

Recently, OLED has gotten spotlights as a next generation planar display. Also, organic compounds for OLED materials have been widely studied. Carbazole is the common starting material for those compounds. In this paper, several carbazole derivative syntheses are reported to cut off the production cost. At the early step of the study, heterogeneous catalysts, which have reusable silica supporters, were used to synthesize carbazole derivatives, which turned out inefficient because of regioisomers inevitably produced. Hence, a new way made with Ullmann cross coupling, reduction, and Tauber carbazole synthesis had been designed. 2-Halogenated nitrobenzene has low cost, so it was used as a starting material. 2,2’-Dinitro-1,1’-biphenyls were synthesized through Ullmann cross coupling with Cu powder. The products were used as substrates to synthesize 2,2’-diamino-1,1’-biphenyls through reduction with ammonium formate which is safer than with hydrogen gas. Finally, the carbazole derivatives were synthesized 17~76% yields through Tauber carbazole synthesis. Not only this procedure, we tried to synthesize carbazole derivatives using anilines as starting material. Through N-acetylation, Tauber carbazole synthesis we synthesized carbazole derivatives 24~61% yields.; 최근 차세대 평판 디스플레이로 OLED(Organic Light Emitting Diodes : 유기 발광 다이오드)가 떠오르고 있다. 이에 따라 OLED에 사용되는 유기화합물인 carbazole 유도체를 합성하기 위한 연구가 많이 진행되고 있다. 대체적으로 사용되는 유기화합물들은 carbazole로부터 합성을 하고 있다. 본 연구에서는 OLED의 기본 원가 절감을 위하여 다양한 carbazole 유도체를 효율적이고 경제적으로 합성할 수 있는 방법을 고안하였다. 연구 초기 단계에는 재사용이 가능한 실리카 지지체를 가지는 불균일 촉매를 통하여 carbazole을 합성하려 했으나 필연적으로 생성되는 regioisomer로 인해 비효율적이라고 판단하였다. 방향을 수정하여 Ullmann cross coupling, Pd/C catalyzed reduction, Tauber carbazole synthesis를 조합한 합성 방법을 고안하였다. 비교적 값이 저렴한 다양한 2-halogenated nitrobenzene들을 출발물질로 하여 Cu powder를 이용한 Ullmann cross coupling을 통해 다양한 2,2’-dinitro-1,1’-biphenyl들을 합성하였다. 합성한 물질들은 수소가스를 사용하지 않는 ammonium formate를 이용한 환원반응을 통하여 비교적 안전하게 2,2’-diamino-1,1’-biphneyl들을 합성하였다. 이를 Tauber carbazole synthesis를 통하여 목표화합물인 다양한 carbazole들을 총 수율 17 ~ 76%로 합성하였다. 또한 보다 더 저렴한 aniline들을 출발물질로 N-acetylation반응, Ullmann cross coupling, Tauber carbazole synthesis를 통하여 보다 더 경제적으로 carbazole들을 총 수율 24~61%로 합성하였다. |Recently, OLED has gotten spotlights as a next generation planar display. Also, organic compounds for OLED materials have been widely studied. Carbazole is the common starting material for those compounds. In this paper, several carbazole derivative syntheses are reported to cut off the production cost. At the early step of the study, heterogeneous catalysts, which have reusable silica supporters, were used to synthesize carbazole derivatives, which turned out inefficient because of regioisomers inevitably produced. Hence, a new way made with Ullmann cross coupling, reduction, and Tauber carbazole synthesis had been designed. 2-Halogenated nitrobenzene has low cost, so it was used as a starting material. 2,2’-Dinitro-1,1’-biphenyls were synthesized through Ullmann cross coupling with Cu powder. The products were used as substrates to synthesize 2,2’-diamino-1,1’-biphenyls through reduction with ammonium formate which is safer than with hydrogen gas. Finally, the carbazole derivatives were synthesized 17~76% yields through Tauber carbazole synthesis. Not only this procedure, we tried to synthesize carbazole derivatives using anilines as starting material. Through N-acetylation, Tauber carbazole synthesis we synthesized carbazole derivatives 24~61% yields.