A system for the sustainable synthesis of novel hydrazinylthiazoles via biomass-derived furfural

Abstract

A system (100) for the synthesis of hydrazinyl thiazoles from furfural obtained from biomass, wherein the system (100) comprises: configured to deliver 5.0 mmol of hydroxylmethylfurfural (HMF), 5.0 mmol of thiosemicarbazide, and 5.0 mmol of phenacyl tosylate; a grinding unit (104) connected to the reactant delivery unit (102) and configured to grind the reactants under ambient conditions for 5 minutes; a reaction monitoring unit (106) comprising thin-layer chromatography (TLC) and connected to the milling unit (104) and configured to monitor the reaction of the reactants during milling; and a purification unit (108) connected to the reaction monitoring unit (106) and configured to isolate the crude compound, followed by recrystallization using a mixture of ethyl acetate and ethanol.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to the field of organic synthesis and pharmaceutical chemistry. More specifically, the present invention relates to a system for the sustainable synthesis of novel hydrazinylthiazole via biomass-derived furfural. BACKGROUND OF THE INVENTION

[0002] A major challenge in modern organic chemistry is the development of environmentally friendly and green organic reactions to address global environmental problems. The principles of green synthesis emphasize the use of environmentally friendly catalysts, solvents, and reagents, while achieving efficient, one-step syntheses of the desired compounds using readily available, low-cost materials. One-pot multicomponent reactions (MCRs) have emerged as a promising approach to realize such ideal syntheses, as they enable the rapid assembly of complex molecules with minimal waste and energy consumption. Among heterocyclic compounds, thiazole and its derivatives are of particular interest due to their diverse biological activities, including antimicrobial, anticancer, anti-inflammatory, antioxidant, and other pharmacological properties.Numerous pharmaceutical active ingredients contain thiazole units as core units, which underlines their therapeutic importance.

[0003] Traditional methods for the synthesis of hydrazinyl thiazoles, such as the Hantzsch synthesis and various modified approaches, have employed catalysts, solvents, or advanced techniques such as microwave and ultrasonic irradiation. While these methods have advanced thiazole chemistry, they often suffer from limitations such as narrow substrate scope, reliance on toxic and non-renewable reagents, the use of expensive or hazardous catalysts, harsh reaction conditions, long reaction times, and lengthy purification procedures. The use of aromatic aldehydes or ketones and phenylacyl bromides in these reactions also poses challenges due to their hazardousness and instability.

[0004] Overcoming these limitations requires an innovative technique that follows the principles of green chemistry and uses sustainable, cost-effective reagents derived from renewable resources. Biomass-derived furfurals, including hydroxymethylfurfural (HMF), have emerged as promising alternatives due to their water solubility, versatility, and potential to act as both solvents and reactants. Furfural-based compounds provide an environmentally friendly basis for the synthesis of hydrazinyl thiazoles, which are believed to exhibit a wide range of biological properties.

[0005] The technical advances disclosed by the present invention overcome the limitations and disadvantages of existing and conventional systems. SUMMARY OF THE INVENTION

[0006] The present invention relates to a system for the sustainable synthesis of novel hydrazinylthiazole via biomass-derived furfural. The system utilizes a grindstone chemistry mechanism to achieve high yields in a short time. The synthesized compounds exhibit significant anticancer activity, with compounds 4d and 4e exhibiting IC50 values ​​of 41.06±0.06 µg / ml and 38.39±0.90 µg / ml against the MCF-7 cell line, respectively. These compounds also exhibit enhanced antibacterial efficacy against Escherichia coli and Bacillus subtilis with MIC values ​​of >6.25 µg / ml and >25 µg / ml, respectively. Furthermore, compounds 4a, 4d, and 4e exhibit remarkable antioxidant activity with IC50 values ​​of 1.58±1.28, 42.36±0.45, and 42.31±0.73 µg / ml, respectively. Molecular docking studies and a structure-activity relationship (SAR) analysis confirm the pharmacological potential of these compounds and support their use in pharmaceutical applications.

[0007] An object of the present invention is to eliminate the need for catalysts and solvents, thereby making the process environmentally friendly and cost-effective.

[0008] Another object of the present invention is to achieve high yields of hydrazinyl thiazole derivatives in significantly shortened reaction times under ambient conditions.

[0009] Another aim of the present invention is to construct a diverse library of hydrazinyl thiazole compounds with potential pharmaceutical applications.

[0010] Another object of the present invention is to evaluate the synthesized compounds for biological activities, including anticancer, antibacterial and antioxidant properties, in order to identify promising candidates for therapeutic use.

[0011] Another aim of the present invention is to demonstrate the advantages of this green chemistry approach over conventional methods, such as ease of handling, high atom economy, and easy product isolation without column chromatography.

[0012] The aim of the present invention is to provide a system for the synthesis of hydrazinyl thiazole from biomass-derived furfural, the system comprising a reactant delivery unit configured to deliver 5.0 mmol of hydroxymethylfurfural (HMF), 5.0 mmol of thiosemicarbazide, and 5.0 mmol of phenacyl tosylate; a milling unit connected to the reactant delivery unit and configured to mill the reactants under ambient conditions for 5 minutes; a thin-layer chromatography (TLC) reaction monitoring unit connected to the milling unit and configured to monitor the reaction of the reactants during milling; and a purification unit connected to the reaction monitoring unit and configured to isolate the crude compound, followed by recrystallization using a mixture of ethyl acetate and ethanol.

[0013] To further clarify the advantages and features of the present disclosure, a more detailed description of the invention will be given with reference to specific embodiments thereof, which are illustrated in the accompanying drawings. It should be noted that these drawings represent only typical embodiments of the invention and are therefore not to be considered limiting its scope. The invention will be described and explained in additional detail and in greater detail with reference to the accompanying drawings. SHORT DESCRIPTION OF THE FIGURE

[0014] These and other features, aspects, and advantages of the present disclosure will be better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters represent like parts throughout. Where: Fig. Figure 1 shows a block diagram of a system for the sustainable synthesis of novel hydrazinyl thiazole compounds via biomass-derived furfural according to one embodiment of the present disclosure.

[0015] Furthermore, those skilled in the art will appreciate that elements in the drawings are shown for convenience and may not necessarily be drawn to scale. For example, the flowcharts illustrate the method by key steps to enhance understanding of aspects of the present disclosure. Furthermore, with respect to the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawing may show only the specific details relevant to understanding embodiments of the present disclosure in order not to clutter the drawings with details that would be readily apparent to those skilled in the art who would benefit from the description herein. DETAILED DESCRIPTION:

[0016] To facilitate an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and described in specific language. It is to be understood, however, that no limitation on the scope of the invention is intended thereby, since such changes and further modifications of the illustrated system and such further applications of the principles of the invention as illustrated therein are contemplated as would normally occur to one skilled in the art to which the invention pertains.

[0017] It will be understood by one skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be limiting thereof.

[0018] References in this specification to "one aspect," "another aspect," or similar language mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, occurrences of the phrase "in one embodiment," "in another embodiment," and similar language throughout this specification may or may not all refer to the same embodiment.

[0019] The terms "comprises," "comprising," or other variations thereof are intended to cover non-exclusive inclusion, such that a process or method comprising a list of steps not only includes those steps, but may also include other steps not expressly listed or inherent in such process or method. Likewise, one or more devices or subsystems or elements or structures or components preceded by "comprises..." does not preclude, without further limitation, the existence of other devices or other subsystems or other elements or other structures or other components or additional devices or additional subsystems or additional elements or additional structures or additional components.

[0020] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The system, methods, and examples provided herein are for illustrative purposes only and should not be considered limiting.

[0021] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0022] Fig.1 shows a block diagram of a system (100) for the sustainable synthesis of novel hydrazinylthiazole via biomass-derived furfural, the system (100) comprising a reactant delivery unit (102) configured to deliver 5.0 mmol of hydroxymethylfurfural (HMF), 5.0 mmol of thiosemicarbazide, and 5.0 mmol of phenacyl tosylate; a milling unit (104) connected to the reactant delivery unit (102) and configured to mill the reactants under ambient conditions for 5 minutes; a thin-layer chromatography (TLC) reaction monitoring unit (106) connected to the milling unit (104) and configured to monitor the reaction of the reactants during milling; and a purification unit (108) connected to the reaction monitoring unit (106) and configured to isolate the crude compound, followed by recrystallization using a mixture of ethyl acetate and ethanol.

[0023] In one embodiment, the milling unit (104) is further equipped with an adjustable speed and pressure setting to optimize the reaction conditions depending on the reactant type.

[0024] In one embodiment, the reaction monitoring unit (106) comprises a digital imaging unit (106a) for capturing and analyzing the TLC results in real time.

[0025] In one embodiment, the purification unit (108) is equipped with a temperature-controlled recrystallization bath to improve product purity and yield.

[0026] The proposed system synthesizes hydrazinyl thiazole from biomass-derived furfural using an environmentally friendly, efficient, and catalyst-free approach. This invention utilizes grindstone chemistry (GSC) to develop a simple, solvent-free, and high-yielding process for the preparation of medically important thiazoles using biomass-derived compounds as the main starting materials. In this innovative process, hydroxymethylfurfural (HMF), a biomass-derived compound, serves as the primary coupling partner in a multicomponent reaction (MCR). The reaction involves hydroxymethylfurfural (5.0 mmol), thiosemicarbazide (5.0 mmol), and phenylacyl tosylate (5.0 mmol) in the absence of catalyst and solvent. Under ambient conditions, the reactants are milled for 20 minutes, resulting in the formation of the desired hydrazinyl thiazole derivative as the sole product in 70% yield.This initial success led to further optimizations to increase product yield and simplify reaction conditions.

[0027] In one embodiment, extensive solvent screening experiments were conducted at room temperature using various solvents, including ethanol, ethanol-water mixtures, dichloromethane (DCM), tetrahydrofuran (THF), THF-water mixtures, 1,4-dioxane-water mixtures, toluene, and dimethylformamide (DMF). However, these experiments did not result in a significant improvement in product yield. A literature review of grindstone chemistry highlighted its suitability for the development of environmentally friendly processes and inspired the complete removal of solvent and catalyst.

[0028] In one embodiment, the starting materials are milled together under optimized conditions at room temperature. Remarkably, the reaction is completed within only five minutes and yields the hydrazinyl thiazole derivative in an exceptional yield of 92%. This rapid and efficient method eliminates the need for column chromatographic purification and further simplifies product isolation.

[0029] Under these optimized conditions, a diverse library of hydrazinyl thiazole derivatives was synthesized from HMF, methylfurfural (MF), thiosemicarbazide, and phenylacyl tosylates as coupling partners. The system achieves good to excellent yields in the range of 85% to 95%, regardless of the electronic properties of the substituents on the phenylacyl tosylate ring. This demonstrates the robustness of the method across a broad substrate scope.

[0030] The reaction mechanism for this transformation involves an initial dehydration reaction between hydroxymethylfurfural and thiosemicarbazide to generate an intermediate, which subsequently reacts with phenylacyl tosylate. Further dehydration and SNi attack lead to a stable intermediate that undergoes proton migration, yielding the hydrazinylthiazole product as the exclusive result.

[0031] In one embodiment, the present system offers several advantages over conventional protocols, including ease of operation, high atom economy, fast reaction time, solvent- and catalyst-free conditions, and easy product isolation. Compared to literature examples, the grindstone chemistry-based approach proves superior in terms of sustainability, efficiency, and scalability.

[0032] In one embodiment, the present invention represents a significant advance in the field of green chemistry and sustainable synthesis, providing a practical and environmentally friendly system for producing hydrazinyl thiazoles with potential medical applications.

[0033] In one embodiment, thiazoles have remarkable antioxidant properties, and their ability to scavenge nitric oxide radicals and inhibit hydrogen peroxide and lipid peroxidation assays has been demonstrated. In particular, derivatives substituted with acetyl and carboxyl groups demonstrated significant antioxidant activity in all tested methods. Furthermore, previous investigations of phenolic thiazole derivatives demonstrated significant antioxidant properties comparable to the present study. The interaction of hydrazinyl thiazole derivatives (4a, 4b, 4c, 4d, 4e, 4f, 4g and 4h) and DPPH in the reaction was demonstrated, therefore it is worth mentioning that derivatives 4a, 4b, 4c, 4d, 4e, 4f, 4g and 4h showed significant antioxidant activity with IC50 values ​​ranging from 41.58 ± 1.28 to 54.18 ± 2.05 µg / ml, compared with standard ascorbic acid (IC50 = 19.59 ± 1.96 µg / ml).The DPPH assay revealed that 4a, 4d, and 4e exhibited the most significant scaffolds with higher IC50 values ​​of 41.58 ± 1.28, 42.36 ± 0.45, and 42.31 ± 0.73 µg / ml, respectively. Furthermore, 4b, 4c, 4f, 4g, and 4h exhibited IC50 values ​​of 43.18 ± 0.64, 52.97 ± 0.78, 54.18 ± 2.05, 53.74 ± 0.38, and 48.10 ± 2.52 µg / ml, respectively. The present invention demonstrated the ability of some compounds to neutralize free radicals using the DPPH assay, which supports previous literature. The antioxidant activity of compounds 4a to 4h is influenced by structural units that contribute to their effectiveness. Compounds 4a, 4c, 4d, and 4f contain a hydroxyl group (-OH) that can donate hydrogen atoms and neutralize free radicals, forming stable phenoxyl radicals, which significantly enhances their antioxidant properties. Compounds 4b, 4e, 4g, and 4h possess a methyl moiety (-CH3), which stabilizes free radicals via a positive inductive effect.The presence of electron-withdrawing groups also plays a crucial role in nitro compounds. The (-NO2) group of 4b and 4c and the nitrile group (-CN) of 4d and 4e stabilize radical intermediates by reducing the electron density of the aromatic ring, which can improve the derivatives' ability to quench free radicals. In compounds 4f and 4g, the chlorine groups (-Cl) and trifluoromethyl groups (-CF3) in 4h further stabilize radicals due to their strong electron-withdrawing nature, thus contributing to antioxidant activity. These combined structural elements—hydroxyl and methyl groups, electron-withdrawing nitro, cyano, and trifluoromethyl groups—work together to enhance the antioxidant potential of compounds 4a to 4h, as observed in the tests.

[0034] The antibacterial activity of the newly synthesized hydrazinyl thiazole derivatives was tested in vitro for activity against Gram-negative bacteria such as E. coli and Gram-positive bacteria such as Bacillus subtilis. The results showed that most compounds exhibited moderate to potent antibacterial activity. In particular, compounds 4d and 4e exhibited increased activity, especially against E. coli with a minimum inhibitory concentration (MIC) of >25 µg / ml and >6.25 µg / ml, respectively, and against Bacillus subtilis with an MIC of >25 µg / ml. This increased activity is attributed to the influence of the 4-cyanophenyl group. Compound 4h, which contains a 4-trifluoromethylphenyl group, also exhibited significant activity against E. coli (MIC >12.5 µg / ml) and Bacillus subtilis (MIC >25 µg / ml). Other derivatives, including 4a, 4b, 4c, 4f and 4g, show remarkable antibacterial activity against the pathogens tested.While the current study is limited to specific pathogens, future research aims to evaluate these derivatives against a wider range of microorganisms to establish a comprehensive antimicrobial profile.

[0035] In one embodiment, the antiproliferative activity of eight hydrazinyl thiazole derivatives is tested using the MTT assay on the human breast cancer cell line (MCF-7). The IC50 values ​​are compared with those of the standard anticancer drug 5-fluorouracil (5-FU; IC50 = 22.69 ± 3.33 µg / ml). Compounds 4d and 4e exhibit the most potent activity with IC50 values ​​of 41.06 ± 0.06 µg / ml and 38.39 ± 0.90 µg / ml, respectively. This enhanced efficacy is attributed to the presence of the 4-cyanophenyl group. Compound 4h, which contains a 4-trifluoromethylphenyl derivative, also exhibits remarkable cytotoxic effects with an IC50 value of 42.17 ± 1.92 µg / mL and induces apoptosis-like properties such as cell shrinkage, membrane blebbing, and reduced cell density. Compounds 4b and 4c exhibit good antiproliferative activity with IC50 values ​​of 47.06 ± 0.31 µg / mL and 51.35 ± 1.28 µg / mL, respectively, while 4f and 4g exhibit moderate activity.These results underline the potential of hydrazinyl thiazole derivatives as promising anticancer agents.

[0036] In one embodiment, the MTT assay confirms that compounds 4d and 4e exhibit the highest antiproliferative activity against the MCF-7 cell line, with IC50 values ​​of 41.06 ± 0.06 µg / ml and 38.39 ± 0.90 µg / ml, respectively. This significant activity underscores the role of electron-withdrawing groups, particularly the 4-cyanophenyl group, in enhancing cell growth inhibition. The nitro derivatives 4b and 4c also exhibit remarkable activity, with IC50 values ​​of 47.06 ± 0.31 µg / ml and 51.35 ± 1.28 µg / ml, respectively, highlighting the importance of aromatic substitutions. Compound 4h, which contains a 4-trifluoromethylphenyl group, exhibits effective cytotoxicity with an IC50 value of 42.17 ± 1.92 µg / ml and induces apoptosis-like effects such as cell shrinkage, membrane blebbing, and reduced cell density. Compounds 4f and 4g exhibit moderate activity with IC50 values ​​of 61.83 ± 1.25 µg / ml and 69.02 ± 3, respectively.18 µg / ml, which is due to the presence of halogen substituents. These results underscore the structural features that are crucial for anticancer efficacy.

[0037] Molecular docking analysis reveals the mechanism of action of the synthesized derivatives against specific biological targets. Using PyRx 0.8, the interaction with Aurora A protein kinase (PDB ID: 4CEG) as a target for anticancer activity shows binding affinities ranging from -8.7 kcal / mol to -8.4 kcal / mol. The most active compounds, 4d and 4e, exhibit binding affinities of -8.7 kcal / mol and form hydrogen bonds with LYS162 and ALA213, as well as Pi interactions such as Pi-alkyl with VAL147 and Pi-sigma with LEU263. In terms of antibacterial activity, docking with E. coli DNA gyrase B (PDB ID: 6KZV) shows binding affinities ranging from -8.2 kcal / mol to -7.4 kcal / mol. Compound 4h exhibits the highest affinity of -8.2 kcal / mol and forms hydrogen bonds with ARG136 and VAL77, pi-alkyl interactions with PRO79 and VAL167, and halogen interactions with VAL43. Compounds 4d and 4e also exhibit strong interactions through hydrogen bonds and pi interactions.Toxicity predictions confirm that all derivatives are non-toxic to normal human cells, including human fetal lung fibroblasts, aortic smooth muscle cells, and foreskin fibroblasts, highlighting their safety and potential for therapeutic applications.

[0038] The drawings and the foregoing description provide examples of embodiments. Those skilled in the art will recognize that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be separated into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of the processes described herein may be changed and are not limited to the manner described herein. Furthermore, the actions of any flowchart need not be implemented in the order shown; nor do all actions necessarily need to be performed. Also, those actions that are not dependent on other actions may be performed in parallel with the other actions. The scope of the embodiments is in no way limited by these specific examples.Numerous variations, whether explicitly stated in the specification or not, such as differences in structure, dimensions, and material use, are possible. The scope of the embodiments is at least as broad as indicated in the following claims.

[0039] Advantages, other benefits, and solutions to problems have been described above with reference to specific embodiments. However, the advantages, benefits, solutions to problems, and any components that may cause an advantage or solution to occur or become more apparent are not to be construed as a critical, required, or essential feature or component of any or all of the claims. REFERENCES 100 A system for the sustainable synthesis of novel hydrazinylthiazoles via biomass-derived furfural. 102 Reactant delivery unit 104 Grinding unit 106 Reaction Monitoring Unit 106a Digital imaging unit 108 cleaning system

Claims

[1] A system (100) for the synthesis of hydrazinyl thiazoles from biomass-derived furfural, the system (100) comprising: configured to deliver 5.0 mmol of hydroxymethylfurfural (HMF), 5.0 mmol of thiosemicarbazide, and 5.0 mmol of phenacyl tosylate; a milling unit (104) connected to the reactant delivery unit (102) and configured to mill the reactants under ambient conditions for 5 minutes; a reaction monitoring unit (106) comprising thin layer chromatography (TLC) and connected to the milling unit (104) and configured to monitor the reaction of the reactants during milling; and a purification unit (108) connected to the reaction monitoring unit (106) and configured to isolate the crude compound, followed by recrystallization using a mixture of ethyl acetate and ethanol. [2] The system (100) of claim 1, wherein the milling unit (104) is further equipped with adjustable speed and pressure settings to optimize the reaction conditions according to the reactant types. [3] The system (100) of claim 1, wherein the reaction monitoring unit (106) comprises a digital imaging unit (106a) to capture and analyze the TLC results in real time. [4] The system (100) of claim 1, wherein the purification unit (108) is equipped with a temperature-controlled recrystallization bath to improve product purity and yield.

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