New pyrazolo[3,4-d]pyrimidine derivatives as EGFR-TK inhibitors: design, green synthesis, potential anti-proliferative activity and P-glycoprotein inhibition

In this study, four series of new pyrazolo[3,4-d]pyrimidine derivatives were designed and synthesized with both green and conventional methods. All the synthesized candidates were chemically confirmed using spectroscopic methods, and the DFT of the reaction mechanism was illustrated. The anti-proliferative activity of the synthesized compounds was evaluated against NCI 60 cancer cell lines. Two compounds (15 & 16) exhibited excellent broad-spectrum cytotoxic activity in NCI 5-log dose assays against the full 60-cell panel with GI50 values ranging from 0.018 to 9.98 μM. Moreover, the enzymatic assessment of the most active derivatives 4, 15, and 16 against EGFR tyrosine kinase showed significant inhibitory activities with IC50 of 0.054, 0.135, and 0.034 μM, respectively. The quantitative real-time PCR for the P-glycoprotein effect of compounds 15 and 16 was examined and illustrated the ability to inhibit the P-glycoprotein by 0.301 and 0.449 fold in comparison to the control. Mechanistic study using reversal activity in MDA-MB-468 cell line revealed the effect of both compounds 15 and 16 cytotoxicity against DOX/MDA-MB-468 with IC50 = 0.267 and 0.844 μM, respectively. Additionally, compound 16 was found to induce cell cycle arrest at the S phase with a subsequent increase in pre-G cell population in MDA-MB-468 cell line. It also increased the percentage of apoptotic cells in a time-dependent manner. Moreover, a molecular docking study was carried out to explain the target compounds' potent inhibitory activity within the EGFR binding site.

New 1,3,4-thiadiazoles as potential anticancer agents: pro-apoptotic, cell cycle arrest, molecular modelling, and ADMET profile

A series of novel 1,3,4-thiadiazoles was synthesized via the reaction of N-(5-(2-cyanoacetamido)-1,3,4-thiadiazol-2-yl)benzamide (3) with different carbon electrophiles and evaluated as potential anticancer agents. The chemical structures of these derivatives were fully elucidated using various spectral and elemental analyses. Out of 24 new thiadiazoles, derivatives 4, 6b, 7a, 7d, and 19 have significant antiproliferative activity. However, derivatives 4, 7a, and 7d were toxic to the normal fibroblasts, and therefore were excluded from further investigations. Derivatives 6b and 19 with IC50 at less than 10 μM and with high selectivity were selected for further studies in breast cells (MCF-7). Derivative 19 arrested the breast cells at G2/M probably through inhibition of CDK1, while 6b significantly increased the sub-G1 percent of cells probably through induction of necrosis. These results were confirmed by the annexin V-PI assay where 6b did not induce apoptosis and increased the necrotic cells to 12.5%, and compound 19 significantly increased the early apoptosis to 15% and increased the necrotic cells to 15%. Molecular docking showed that compound 19 was like FB8, an inhibitor of CDK1, in binding the CDK1 pocket. Therefore, compound 19 could be a potential CDK1 inhibitor. Derivatives 6b and 19 did not violate Lipinski's rule of five. In silico studies showed that these derivatives have a low blood-brain barrier penetration capability and high intestinal absorption. Taken together, derivatives 6b and 19 could serve as potential anticancer agents and merit further investigations.

The Reformatsky analogous reaction for the synthesis of novel β-thioxoesters via using aroyl isothiocyanates under solvent-free ball milling and conventional conditions

The classical Reformatsky reaction, initially described in 1887, is considered one of the most useful ways of forming C-C bonds. The target of this work includes improving the Reformatsky reaction between aroyl isothiocyanates and α-haloesters using metallic zinc to form β-thioxoesters (3-11). In this procedure, a new metal-mediated carbon-carbon linkage is formed with the formation of an organozinc halide and decomposition due to the presence of dilute acid, affording a good yield of the desired product via conventional techniques and ball milling. The Reformatsky reaction requires no solvent and no inert gases.

New N-(1,3,4-thiadiazol-2-yl)furan-2-carboxamide derivatives as potential inhibitors of the VEGFR-2

The present study reports the synthesis and biological evaluation of a new series of novel N-(1,3,4-thiadiazol-2-yl)furan-2-carboxamide derivatives. The reactions were executed under both conventional and microwave irradiation conditions. An enhancement in the synthetic yields and rates was observed when the reactions were carried out under the microwave compared with the classical conditions. The structures of the products were ascertained by different analytical and spectral analyses. The antiproliferative activities were evaluated against three human epithelial cell lines; breast (MCF-7), colon (HCT-116), and prostate (PC-3) using MTT assay technique and doxorubicin was utilized as a reference drug. Besides, molecular docking studies were also performed and the vascular endothelial growth factor recptor-2 (VEGFR-2) was identified as a potential molecular target. Compounds 6, 7, 11a, 11b, 12, 14, and 16 showed promising antiproliferative activity against the three cancer cell lines investigated. Compounds 2 and 15b had significant antiproliferative activities against only colon and breast cells but not against the prostate cells. All the active antiproliferative compounds were highly selective. All the active antiproliferative compounds were good inhibitors of the VEGFR-2 at 7.4-11.5 nM compared with Pazopanib. Compound 7 with the most favorable orientation to the VEGFR-2 from the docking studies, was also the best inhibitor of the receptor. The antiproliferative activity of these compounds is in partial caused by their ability to inhibit the VEGFR-2 and since other molecular targets were not examined, other possibilities cannot be ruled out.

Utility of 3-(thiophen-2-yl)prop-2-enoyl isothiocyanate in heterocyclic synthesis

Convenient syntheses of quinazoline, benzothiazole, thiadiazole, imidazole, and thiourea derivatives starting from 3-(thiophen-2-yl)prop-2-enoyl isothiocyanate are described. The structures of the synthesized compounds are confirmed from their microanalytical and spectral data. Some of the products are examined for their antibacterial activity against Gram-positive and Gram-negative bacteria and fungi.

Synthesis and Antimicrobial Activity Evaluation of Some Novel Hydrazone, Pyrazolone, Chromenone, 2-Pyridone and 2-Pyrone Derivatives

A cyanoacetohydrazide derivative underwent a series of reactions with different nucleophilic reagents, such as hydrazine hydrate, p-chlorobenzaldehyde and salicylaldehyde, to give the condensation products. In addition, an arylidene malononitrile was reacted with different nitrogen nucleophiles, such as hydrazine hydrate, thiocarbohydrazide and cyanoacetohydrazide, to afford the hydrazine, hydrazone and pyridin-2-one derivatives, respectively. Furthermore, a pyridin-2-one derivative was reacted with different carbon electrophiles, such as carbon disulfide, p-chlorobenzaldehyde and acetic anhydride. The antimicrobial activities of some of the compounds were examined.

Synthesis and Antimicrobial Assessments of Some Quinazolines and Their Annulated Systems

The syntheses of some new derivatives of quinazoline and their annulated derivatives are described in this work. Investigation of antimicrobial activity of the new products was evaluated using agar well diffusion methods with determination of minimal inhibitory concentrations against six pathogenic bacteria and three pathogenic fungi. Most of the new compounds are potent as antimicrobial agents.

Multicomponent synthesis of 4-arylidene-2-phenyl-5(4H)-oxazolones (azlactones) using a mechanochemical approach

BACKGROUND

Mechano heterocyclic chemistry (MCH) is a recent quickly growing technique in the synthesis of heterocycles and draws the attention of heterocyclic chemists towards the uses of grindstone technique in a solvent free green efficient synthesis of many heterocyclic systems. On the other hand, multicomponent approach has opened the door for the rapid and efficient one-step procedures to synthesize a wide range of complex targets. Azlactones have been reported to exhibit a wide range of pharmaceutical properties including immune suppressive, anticancer. Antimicrobial, antitumor, anti-inflammatory and antiviral. It also used as useful synthons in the synthesis of several small molecules, including amino acids and peptides.

RESULTS

The present work describes an efficient one step green synthesis of 4-arylidene-2-phenyl-5(4H)-oxazolones (azlactones) via the multi-component synthesis by the mechanochemical grinding of glycine, benzoyl chloride, an aromatic aldehyde and fused sodium acetate in the presence of drops of acetic anhydride. This process is green, simple to handle, step and atom efficient, economical and environmentally friendly, because it does not require a reaction solvent or heating, we introduced the yield economy [YE] as a metric to assess the conversion efficiency of grinding and conventional synthetic reactions of azlactones. The structures of the newly synthesized compounds were elucidated by elemental and spectral analyses.

CONCLUSION

In conclusion, we have developed a simple, efficient and eco-friendly strategy for facile synthesis of azlactones. The key advantages of this strategy, over conventional approach, include its simple, solvent free conditions, as well as its facile work-up, high yield economy and environmental friendliness. It is also successful in achieving three of the green chemistry objectives of a solvent free operation, high atom economy and step efficient. Thus, combining the features of both economic and environmental advantages.Graphical abstractAn efficient one step green synthesis of azlactones via multicomponent synthesis by a mechanochemical grinding.

Use of Disubstituted Thiosemicarbazide in Synthesis of New Derivatives of 1,3,4-Thiadiazole, 1,2,4-Triazole and Pyrazole with Their Antimicrobial Evaluation

New derivatives of 1,3,4-thiadiazole, 1,2,4-triazole and pyrazole were obtained by cyclisation of the corresponding disubstituted thiosemicarbazide derivative. The newly synthesised derivatives were obtained in good yields and their structures were elucidated by spectral data and elemental analyses. The antimicrobial activity of some of the synthesised compounds is tested.

Use of dodecanoyl isothiocyanate as building block in synthesis of target benzothiazine, quinazoline, benzothiazole and thiourea derivatives

Dodecanoyl isothiocyanate (

Synthesis of Some New Phthalazines and their Evaluation as Corrosion Inhibitors of Steel

A convenient synthesis has been achieved of 11 substituted phthalazines starting from the condensation of 2-( p-toluoyl)benzoic acid with hydrazine and some of its simple congeners, H2NNHR. Four of the phthalazines showed activity as inhibitors of the corrosion of steel immersed in 5 M HCl solutions.

Synthesis and Antimicrobial Study of 1,2,4-Triazole, Quinazoline and Benzothiazole Derivatives from 1-Naphthoylisothiocyanate

1-Naphthoylisothiocyanate (1) is used as a building block in the synthesis of 1,2,4-triazole, quinazoline, benzothiazole and thiourea derivatives. The antimicrobial activity of some of the synthesised compounds was tested.

Hydrazine Derivatives and O-Benzoylbenzoic Acid as a Source of Phthalazines with their Antimicrobial Activities

Starting from 2-benzoylbenzoic acid (1) and prototype hydrazine itself or some of its simple congeners produce phthalazin-1(2H)-one derivatives 2a–d. Reactions of 2 with P2S5 or POCl3 gave their thione derivatives 3a–c or the chloro derivative 4 respectively. Further reactions of phthalazines 3 and 4 with hydrazine derivatives afforded their hydrazinyl derivatives 5a–d. Compounds 5a and 5d were used as a precursor to triazolo 6 and pyrazolyl phthalazines 7. The antimicrobial activities of some of the prepared phthalazines were tested.

α-Enones in heterocyclic synthesis of indazole, thiazine, chromene and quinoline derivatives with their antimicrobial activities

α-Enones 1a,b react additively with hydrazine hydrate, thiourea, diethyl malonate, malononitrile, as well as ethyl cyanoacetate. Simultaneous cyclisation of the resulting 1:1 adducts yields indazole, thiazine, chromene and quinoline derivatives. The structures of all the synthesised compounds were confirmed by micro analytical and spectral data. The antimicrobial activity of some of the synthesised compounds were tested.

Addition–cyclisation of 3-(2-thienyl)acryloyl isothiocyanate with hydrazine derivatives as a source of triazoles and thiadiazoles

3-(2-Thienyl)acryloyl isothiocyanate reacts additively with hydrazine hydrate, phenylhydrazine, 2-pyridyl hydrazine, (thio) semicarbazides, as well as benzoyl- and ethoxycarbonyl hydrazine. Simultaneous or subsequent cyclisation of the resulting 1:1 adducts in acidic or alkaline media yields substituted 1,3,4-thiadiazoles or 1,2,4-triazoles respectively.

Synthesis of 1,2,4-triazoles, imidazoles, pyrimidines, quinazolines, 1,3,5-triazines, and 1,3-thiazines from 3-oxo-5,6-diphenyl-2,3-dihydro-pyridazine-4-carbonyl isothiocyanate

3-Oxo-5,6-diphenyl-2,3-dihydropyridazine-4-carbonyl isothiocyanate (1) was reacted with hydrazine hydrate, or phenyl hydrazine, to give 1,2,4-triazole derivatives in a one pot-reaction. However, reaction of 1 with benzoyl hydrazine afforded thiourea derivative that was cyclised to a differently substituted 1,2,4-triazole. Ethyl glycinate reacted with isothiocyanate 1 to give an adduct that was cyclised to imidazolidine derivative. Reaction of 1 with o-aminophenol, o-phenylenediamine or o-aminothiophenol afforded benzoxazole, benzimidazole or benzothiazole derivatives respectively. Reaction of 1 with thioglycolic acid gave 1,3-thiazine derivative, however, when 1 was treated with anthranilic acid a thiourea derivative was obtained which cyclised to a quinazoline derivative. Reaction of 1 with 2-cyanoacetamide or guanidine HCl yielded pyrimidine or triazine derivatives respectively. The structures of all compounds were confirmed by their micro analytical and spectral data.