TY - JOUR AU - Kemskіі, S. V. AU - Boyko, Yu. S. AU - Bolbut, A. V. AU - Suykov, S. Yu. AU - Kyrylchuk, A. A. AU - Vovk, M. V. PY - 2016/09/19 Y2 - 2024/03/29 TI - 4-Aminosubstituted 1,6-dyhidropyrazolo[3,4-e][1,4] diazepines: the synthesis, NMR-spectral and quantum-chemical study JF - Journal of Organic and Pharmaceutical Chemistry JA - J. Org. Pharm. Chem. VL - 14 IS - 3(55) SE - Original Researches DO - 10.24959/ophcj.16.896 UR - https://ophcj.nuph.edu.ua/article/view/ophcj.16.896 SP - 43-51 AB - The role of the structural modification of 1,4-benzodiazepine systems with dialkylamino groups previously used successfully for a number of important derivatives possessing a complex of specific biological properties has been noted. This paper significantly expands the variety of hetero-annelated diazepines by developing a preparatively convenient synthetic route of new amino substituted pyrazol[3,4-e][1,4]diazepines. For this purpose, the reaction of 4-chloro-1,6-dihydropyrazolo[3,4-e][1,4]diazepines with the primary alkyl (aryl) amines and the secon- dary cycloalkylamines has been studied in detail. It has been found that this interaction occurs under 8-10 hour reflux in ethanol and for the primary and secondary alkylamines it leads to 4-amino-1,6-dihydropyrazolo[3,4-e] [1,4]diazepine hydrochlorides, and in case of aryl amines – to their corresponding free bases with high yields. The reaction of the secondary amines has been shown to be very sensitive to their steric parameters: dietyl- or diisopropylamines do not interact with 4-chloro derivatives of 1,6-dihydropyrazolo[3,4-e][1,4]diazepines. The structure of the compounds synthesized is consistent with the results of elemental analysis, LS/MS-, IR- and NMR-spectra. The COSY and EXSY methods were used for reliable identification of signals of cycloalkylamino substituents of 1,6 dihydropyrazolo[3,4-e][1,4]diazepines. Changes in NMR-spectra during protonation of 5-cycloalkylaminopyrazolodiazepines correspond to the results of quantum chemical simulations, according to them the preferred structure is the one with the protonated nitrogen atom in position 5 of the pyrazolodiazepine system. ER -