Abeed Ahmed Abdou O, El-Emary Talaat, Alharthi Sarah
Department of Chemistry, Faculty of Science, Assiut University, Assiut, 71516, Egypt.
Department of Chemistry, College of Science, Taif University, P.O. Box 11099 Taif, 21944, Saudi Arabia.
Curr Org Synth. 2022;19(1):177-185. doi: 10.2174/1570179418666210809144906.
This paper showed the synthetic capability of the indolo[2,3-b]quinoxaline nucleus to be provided as an excellent precursor for the synthesis of various heterocyclic compounds. These synthetic routes proceed via the formation of 3-(6H-indolo[2,3-b]quinoxalin-6-yl) propane hydrazide (2). The carbohydrazide 2 and its reactions with different reagents give five and six-membered rings, such as 1,3,4-thiadiazole, 1,3,4- oxadiazole, 1,2,4-triazole, and 1,2,4-triazine.
All chemicals used in the current study were of analytical grade. Melting points were determined using an APP Digital ST 15 melting point apparatus and were uncorrected. FT-IR spectra were recorded on a Pye- Unicam SP3-100 and Shimadzu-408 spectrophotometers in KBr pellets and given in (cm) KBr. The NMR spectra were detected by a Bruker AV-400 spectrometer (400 MHz for H, 100 MHz for C and 40.55 MHz for N), Institute of Organic Chemistry, Karlsruhe, Germany. Chemical shifts were expressed as δ (ppm) with TMS as an internal reference. Mass spectrometry was provided on a Varian MAT 312 instrument in EI mode (70 eV).
The target compounds were obtained, and their structures were completely elucidated by various spectral and elemental analyses (Ft-IR, H-NMR, ;C-NMR, and mass spectrometry).
The current work showed a view of the reactivity of the carbohydrazide group. The carbohydrazide 2 was obtained from the hydrazinolysis of carboethoxy compound 1 and exploited as a key intermediate to synthesize heterocyclic compounds with different rings.
本文展示了吲哚并[2,3 - b]喹喔啉核的合成能力，它可作为合成各种杂环化合物的优良前体。这些合成路线通过形成3-(6H - 吲哚并[2,3 - b]喹喔啉 - 6 - 基)丙烷酰肼(2)来进行。酰肼2及其与不同试剂的反应生成五元环和六元环，如1,3,4 - 噻二唑、1,3,4 - 恶二唑、1,2,4 - 三唑和1,2,4 - 三嗪。
本研究中使用的所有化学试剂均为分析纯。熔点使用APP Digital ST 15熔点仪测定，未进行校正。傅里叶变换红外光谱(FT - IR)在Pye - Unicam SP3 - 100和岛津 - 408分光光度计上以KBr压片形式记录，并以(cm⁻¹)KBr给出。核磁共振光谱由德国卡尔斯鲁厄有机化学研究所的布鲁克AV - 400光谱仪检测(氢谱为400 MHz，碳谱为100 MHz，氮谱为40.55 MHz)。化学位移以δ(ppm)表示，以四甲基硅烷(TMS)作为内标。质谱在瓦里安MAT 312仪器上以电子轰击(EI)模式(70 eV)提供。
获得了目标化合物，并通过各种光谱和元素分析(傅里叶变换红外光谱、氢核磁共振谱、碳核磁共振谱和质谱)完全阐明了它们的结构。
当前工作展示了酰肼基团的反应活性。酰肼2由碳乙氧基化合物1的肼解反应得到，并被用作合成不同环系杂环化合物的关键中间体。
