Novel N-(3-ethynyl Phenyl)-6,7-bis(2-methoxyethoxy)Quinazoline-4-amine Derivatives: Synthesis, Characterization, Anti-cancer Activity, In-silico and DFT Studies.

BACKGROUND: Cancer is one of the most common reasons for mortality in the world. A continuous effort to develop effective anti-cancer drugs with minimum side effects has become necessary. The use of small-molecule drugs has revolutionized cancer research by inhibiting cancer cell survival and proliferation. Quinazolines are a class of bioactive heterocyclic compounds with active pharmacophores in several anti-cancer drugs. Such small molecule inhibitors obstruct the significant signals responsible for cancer cell development, thus blocking these cell signals to prevent cancer development and spread. OBJECTIVE: In the current study, novel quinazoline derivatives structurally similar to erlotinib were synthesized and explored as novel anti-cancer agents. METHODS: All the synthesized molecules were confirmed by spectroscopic techniques like 1H NMR, 13C NMR, and ESI-MS. Various techniques were applied to study the protein-drug interaction, DFT analysis, Hirshfeld surface, and target prediction. The molecules were screened in vitro for their anti-cancer properties against 60 human tumor cell lines. The growth inhibitory properties of a few compounds were studied against the MCF7 breast cancer cell line. RESULTS: The activity of compounds 9f, 9o, and 9s were found to be active. However, compound 9f is more active when compared with other compounds. CONCLUSION: Some synthesized compounds were active against different cancer cell lines. The in-vitro study results were found to be in agreement with the predictions from in-silico data. The selected molecules were further subjected to get the possible mechanism of action against different cancer cells.

Identification, Synthesis, and Characterization of Potential Oxidative Impurities of Venetoclax: Application of Meisenheimer Rearrangement.

Venetoclax is a potent BCL-2 inhibitor that is used for the treatment of several blood cancers. During the oxidative stress degradation of venetoclax, we observed the formation of two potential impurities at levels of about 8-10%, which have similar molecular weights. The two impurities were isolated and identified as 4-(3-((1H-pyrrolo[2,3-b]pyridin-5-yl)oxy)-4-(((3-nitro-4-(((tetrahydro-2H-pyran-4-yl)methyl)amino)phenyl)sulfonyl)carbamoyl)phenyl)-1-((4'-chloro-5,5-dimethyl-3,4,5,6-tetrahydro-[1,1'-biphenyl]-2-yl)methyl)piperazine 1-oxide (venetoclax N-oxide, VNO) and 2-((1H-pyrrolo[2,3-b]pyridin-5-yl)oxy)-4-(4-((4'-chloro-5,5-dimethyl-3,4,5,6-tetrahydro-[1,1'-biphenyl]-2-yl)methoxy)piperazin-1-yl)-N-((3-nitro-4-(((tetrahydro-2H-pyran-4-yl)methyl)amino)phenyl)sulfonyl)benzamide (venetoclax hydroxylamine impurity, VHA). To confirm these two compounds, we have synthesized each impurity individually and analyzed it by high-performance liquid chromatography, mass spectrometry, 1H NMR, 13C NMR, and 2D NMR. VNO was synthesized by the oxidation of venetoclax using m-CPBA in dichloromethane to get the required N-oxide impurity. After the confirmation of the VNO impurity, the VNO impurity was heated with water at reflux in a sealed tube for 36 h to get the VHA impurity of about 6-8% after 36 h. After thorough analysis, it was confirmed that venetoclax N-oxide undergoes [1,2] Meisenheimer rearrangement to form the venetoclax hydroxylamine impurity. These two impurities may be relevant reference standards in manufacturing venetoclax Active Pharmaceutical Ingredient (API) (or) tablets.

Identification, Synthesis, and Characterization of Novel Baricitinib Impurities.

Baricitinib is a novel active pharmaceutical ingredient used in the treatment of rheumatoid arthritis, and it acts as an inhibitor of Janus kinase. During the synthesis of baricitinib, three unknown impurities were identified in several batches between 0.10 and 0.15% using high-performance liquid chromatography. The unknown compounds were isolated and identified as N-((3-(4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl)-5-oxotetrahydrofuran-3-yl)methyl)ethane sulfonamide (lactone impurity, BCL), 2-(3-(4-(7H-[4,7'-bipyrrolo[2,3-d]pyrimidin]-4'-yl)-1H-pyrazol-1-yl)-1-(ethylsulfonyl)azetidin-3-yl)acetonitrile (dimer impurity, BCD), and 2-(1-(ethylsulfonyl)-3-(4-(7-(hydroxymethyl)-7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl)azetidin-3-yl) acetonitrile (hydroxymethyl, BHM). These compounds were synthesized and confirmed against the isolated samples. The structures of all the three impurities were confirmed by extensive analysis of 1H NMR, 13C NMR, and mass spectrometry. The lactone impurity formation was explained by a plausible mechanism. The outcome of this study was very useful for scientists working in process as well as in formulation development. To synthesize highly pure baricitinib drug substance, these impurities can be used as reference standards due to their potential importance.