2,7-二溴-N-辛基咔唑的合成与表征

Synthesis and Characterization of 2,7-Dibromo-N-octylcarbazole

摘要:

以4,4，-二溴联苯为原料经硝化、闭环、N-烷基化反应合成了2,7-二溴-N-辛基咔唑(3)。4,4，-二溴联苯与发烟硝酸按n(4,4，-二溴联苯)︰n(HNO3)=1.0︰4.0，在75 ℃下进行硝化，反应5 h，得到了2-硝基-4,4，-二溴联苯(1)，收率97%；中间产物1与三苯基膦按n(2-硝基-4,4，-二溴联苯)︰n(三苯基膦)=1.0︰3.0，在无水无氧条件下，闭环得到了2,7-二溴咔唑(2)，收率68%；在碱性条件下，中间产物2与1-溴辛烷按n(2,7-二溴咔唑)︰n(1-溴辛烷)=1.0︰1.5，N-烷基化反应合成最终产物，收率85%。产物结构经IR、元素分析和1H NMR确证。

Abstract:

2,7-Dibromo-N-octylcarbazole (3) was synthesized from 4,4，-dibromobiphenyl by nitration, the Cadogan cyclization and N-alkylation. Nitration of 4,4，-dibromobiphenyl by HNO3 with n(4,4，-dibromobiphenyl)︰n(HNO3)=1.0︰4.0 gave 4,4，-dibromo-2-nitrobiphenyl (1) with a yield of 97% at 75 ℃ for 5 h. The cyclization of 1 by triphenylphosphine with n(4,4，-dibromo-2- nitrobiphenyl) : n(triphenylphosphine)=1.0 : 3.0 gave 2,7-dibromocarbazole (2) with a yield of 68% in Schlenk flask. N-alkylation of 2 by bromooctane with n(2,7-dibromocarbazole) : n(bromooctane)=1.0 : 1.5 gave the title product with a yield of 85% under the alkaline conditions. The structure of the product was characterized by IR, elementary analysis and 1H NMR spectra.