Syntheses Of The New N-pyrazole Carbazole Compounds

Heterocyclic compounds is an important material of synthetic drugs. It was found that combination of different heterocyclic compounds can greatly enhance the biological activity of a single.Carbazole and pyrazole as a simple small molecules, they are the important starting material of synthesis of novel heterocyclic compounds,they are likely to be a good combination of drug intermediates. In this guidance, it was synthesized 9-(3-(pyrazolyl-1-yl)- 9H-carbazole, 9-(3-(4-nitropyrazolyl-1-yl)propyl)-9H-carbazole, 9-(3-(3-methylpyrazolyl-1- yl)propyl)-9H-carbazole, 3,6-dibromo-9-(3-(pyrazoly-l-1-yl)propyl)-9H-carbazole and 3,6- diochloro-9-(3-(pyrazolyl-1-yl)propyl)-9H-carbazole in this paper.9-(3-bromopropyl)-9H-carbazole was obtained by N-alkylation of carbazole and 1,3- dibromopropane as the raw materials,the yield was 63.2%. Carbazole as a fixed feeding was 2g, and the better technological conditions was obtained by orthogonal, i.e. the molar ratio of carbazole to 1,3- dibromopropane was 1:2, the temperature was 20℃, the reaction time was 10 hours, the solvent was 30mL. Finally 9-(3-(pyrazolyl-1-yl)propyl)-9H-carbazole was synthesized from pyrazole and 9-(3-bromopropyl)-9H-carbazole with two methods. The yield of the product could reach 73.4% by using heating cover in one method. The yield could reach 85.7% by microwave devices in another method. Comparison of two methods, the former's time was very long, and the latter's time was very short and yield was higher. 3,6-diochlorocarbazole was obtained by the the method of NCS, the yield was 78.5%. 3,6- diochloro-9-(3-bromopropyl)-9H-carbazole was obtained by N-alkylation of 3,6-diochloro- carbazole and 1,3- dibromopropane as the raw materials. The yield was 53.7%. Finally, 3,6- diochloro-9-(3-(pyrazolyl-1-yl)propyl)-9H-carbazole was synthesized from and pyrazole with microwave devices,the yield was 80.7%. 3,6- diochloro-9-(3-bromopropyl)-9H- carbazole as a fixed feeding was 1.08g and microwave power was 300W, and the better technological conditions was obtained by orthogonal, i.e. the molar ratio of 3,6-diochloro-9-(3- bromopropyl)-9H-carbazole to pyrazole was 1:2,the temperature was 100℃,the reaction time was 30min, the solvent was 15mL.3,6-dibromo-carbazole was obtained by the method of NBS, and the yield was 68.5%. 3,6- diobromo-9-(3-bromopropyl)-9H-carbazole was obtained by N-alkylation of 3,6-diobromo -carbazole and 1,3- dibromopropane as the raw materials. The yield was 63.4%. Finally,3,6- diobromo-9-(3-(pyrazolyl-1-yl) propyl)-9H-carbazole was synthesized from 3,6- diobromo-9- (3-bromopropyl)-9H- carbazole and pyrazole. The yield was 80.1%. 1-nitro-pyrazole was obtained by nitration of pyrazole, the yield was 84.1%. Then, 4- nitro-pyrazole was obtained by rearrangement of 1-nitro-pyrazole. The better technological conditions had been obtained by single factor experiments, i.e. 1-nitro-pyrazole was 5.7g, concentrated sulfuric acid was 5mL, under the 0℃temperature the reaction time was 3 h. The average yield was 74.46%. Finally, 9-(3-(4-nitropyrazolyl-1-yl)propyl)-9H-carbazole was synthesized from 4-nitro-pyrazole and 9-(3-bromopropyl)-9H-carbazole, the yield was 67.3 %.9-(3-(3-methylpyrazolyl-1-yl)propyl)-9H-carbazole was compound from 3-methy-pyrazole and 9-(3-bromopropyl)-9H-carbazole, and the yield was 87.3%. By using different bases and solvents as the reaction conditions, the control experiments reached KOH as base and DMF as solvent was best.