Reaction Of Formaldehyde Research Articles

Efficient synthesis of camptothecin propargylamine derivatives in water catalyzed by macroporous adsorption resin-supported gold nanoparticles

In this work, for the first time, we report an efficient, simple strategy for synthesizing active camptothecin (CPT) derivatives in water. A novel macroporous adsorption resin-supported gold nanoparticle (MAR-AuNP) was first in situ prepared in water. The resulting MAR-AuNPs swell in water and were applied not only as an efficient adsorbent for hydrophobic CPT molecules, but also as a catalyst for the Mannich reaction of CPT, formaldehyde and amines with water as a solvent. A series of novel CPT propargylamine derivatives were successfully obtained with high yields by virtue of such a strategy. Moreover, the resulting CPT propargylamine derivatives exhibited excellent cytotoxicity against two different tumor cell lines. This novel and efficient strategy, avoiding the use of toxic solvents, represents a promising green route for drug discovery from natural products and shows great potential in the green pharmaceutical industry.

Synthesis and biological evaluation of aminomethyl and alkoxymethyl derivatives as carbonic anhydrase, acetylcholinesterase and butyrylcholinesterase inhibitors

Compounds containing nitrogen and sulfur atoms can be widely used in various fields such as industry, medicine, biotechnology and chemical technology. Therefore, the reactions of aminomethylation and alkoxymethylation of mercaptobenzothiazole, mercaptobenzoxazole and 2-aminothiazole were developed. Additionally, the alkoxymethyl derivatives of mercaptobenzoxazole and 2-aminothiazole were synthesized by a reaction with hemiformals, which are prepared by the reaction of alcohols and formaldehyde. In this study, the inhibitory effects of these molecules were investigated against acetylcholinesterase (AChE), butyrylcholinesterase (BChE) enzymes and carbonic anhydrase I, and II isoenzymes (hCA I and II). Both hCA isoenzymes were significantly inhibited by the recently synthesized molecules, with Ki values in the range of 58–157 nM for hCA I, and 81–215 nM for hCA II. Additionally, the Ki parameters of these molecules for BChE and AChE were calculated in the ranges 23–88 and 18–78 nM, respectively.

Synthesis of Quinazoline derivatives and its Antimicrobial Activity

Heterocyclic rings containing nitrogen atom are important class of compounds for the medicinal chemist. Quinazoline nucleus has attracted attention of medicinal chemists, due to wide spectrum of biological activities shown by them. Synthesis of some 3-substituted-4-(2H)-quinazolinones has been carried out by the reaction of anthranilic acid, formaldehyde and primary aromatic amines. Characterization of compound is carried out by using IR and NMR spectroscopy. Its antimicrobial activity is performed against Staphylococcus aureus using Nutrient Agar Medium. Total four compounds were tested for antimicrobial activity. The compound having nitro group possess maximum antimicrobial activity.

Identification of Protein Thiazolidination as a Novel Molecular Signature for Oxidative Stress and Formaldehyde Exposure.

Chemical modifications of proteins have been well-documented to play important roles in normal cell physiology such as cell signaling and protein functions. They have also been demonstrated to be one of the milestones in the pathophysiology of many human diseases such as cancer, age-related pathology, and neurodegenerative disorders. Here, we report the initial identification of a novel protein modification, cysteine thiazolidination, through reaction with endogenous and exogenous formaldehyde with cysteine residues in proteins. Using an isotope-dilution liquid chromatography-tandem mass spectrometric (LC-MS3) method, we initiated the study by quantitating thioproline in formaldehyde-treated Escherichia coli (E. coli) protein. The study was then extended to quantitate thioproline in protein obtained from formaldehyde- and oxidant-exposed E. coli. Furthermore, N6-formyllysine, a well-defined formylation product between formaldehyde and lysine, was exploited in a comparative study to evaluate the relative reactivity and amount of cysteine thiazolidination in the reaction of formaldehyde with proteins. It is anticipated that cysteine thiazolidination may serve as a novel biomarker for oxidative stress and formaldehyde exposure.

Facile synthesis of fluorinated resorcinol-formaldehyde aerogels

In this paper, we have tried to use some unconventional solvents for the preparation of resorcinol-formaldehyde (RF) aerogels. The nature of the gelation solvent is found to greatly influence the properties of RF aerogels, e.g., to affect the specific surface area. Fluorination of aerogels’ matrix is shown to take place upon synthesis of lyogels in the hexafluoroacetone medium. Fluorination proceeds by the mechanism of electrophilic substitution reaction in a resorcinol cycle with a formation of a CC bond. Unprecedented acceleration of the reaction of formaldehyde with resorcinol to form the RF-resin matrix under the action of hexafluoroacetone is observed. The results presented provide the first example of organic aerogels fluorination by electrophilic substitution reaction.

Simulated reaction of formaldehyde and ambient atmospheric particulate matter using a chamber

The reaction of HCHO with Beijing winter's real ambient particulate matter (PM) inside a 3.3m3 Teflon Chamber was conducted in this study. NO2, O3 and H2O gases were removed from the ambient aerosol before entering into the chamber. The decays of HCHO were monitored (acetylacetone spectrophotometry method) during the reactions at different PM number concentrations (Na) and relative humidities (RHs), and the formed particulate formate was detected by IC and XPS techniques. The results showed that when RH was 10%–15%, the decay rate of HCHO in the chamber was higher with the existence of PM from relatively clean days (with number concentration (Na)<200,000particle/L, 0.35–22.5μm) compared to dirty days (Na>200,000particle/L, 0.35–22.5μm). When RH increased to 30%–45%, PM can hardly have significant influences on the decay of HCHO. The formations of formate on the reacted PM were consistent with the HCHO decay rates at different ambient PM Na and RH conditions. This is a first study related to the “real” ambient PM reacted with HCHO and suggested that in the clean and low RH days, PM could be an effective medium for the conversion of HCHO to formate.

The Effectors and Sensory Sites of Formaldehyde-responsive Regulator FrmR and Metal-sensing Variant

The DUF156 family of DNA-binding transcriptional regulators includes metal sensors that respond to cobalt and/or nickel (RcnR, InrS) or copper (CsoR) plus CstR, which responds to persulfide, and formaldehyde-responsive FrmR. Unexpectedly, the allosteric mechanism of FrmR from Salmonella enterica serovar Typhimurium is triggered by metals in vitro, and variant FrmRE64H gains responsiveness to Zn(II) and cobalt in vivo. Here we establish that the allosteric mechanism of FrmR is triggered directly by formaldehyde in vitro. Sensitivity to formaldehyde requires a cysteine (Cys35 in FrmR) conserved in all DUF156 proteins. A crystal structure of metal- and formaldehyde-sensing FrmRE64H reveals that an FrmR-specific amino-terminal Pro2 is proximal to Cys35, and these residues form the deduced formaldehyde-sensing site. Evidence is presented that implies that residues spatially close to the conserved cysteine tune the sensitivities of DUF156 proteins above or below critical thresholds for different effectors, generating the semblance of specificity within cells. Relative to FrmR, RcnR is less responsive to formaldehyde in vitro, and RcnR does not sense formaldehyde in vivo, but reciprocal mutations FrmRP2S and RcnRS2P, respectively, impair and enhance formaldehyde reactivity in vitro. Formaldehyde detoxification by FrmA requires S-(hydroxymethyl)glutathione, yet glutathione inhibits formaldehyde detection by FrmR in vivo and in vitro. Quantifying the number of FrmR molecules per cell and modeling formaldehyde modification as a function of [formaldehyde] demonstrates that FrmR reactivity is optimized such that FrmR is modified and frmRA is derepressed at lower [formaldehyde] than required to generate S-(hydroxymethyl)glutathione. Expression of FrmA is thereby coordinated with the accumulation of its substrate.

Interaction of Formaldehyde with the Rutile TiO2(110) Surface: A Combined Experimental and Theoretical Study

The adsorption and reaction of formaldehyde (CH2O) on the oxidized rutile TiO2(110) surface were studied by temperature-programmed desorption (TPD), scanning tunneling microscopy (STM), infrared reflection–absorption spectroscopy (IRRAS), and density functional theory (DFT) calculations. The experimental and theoretical data reveal the presence of various species depending on the temperature and coverage. Exposure to formaldehyde at 65 K leads to the formation of CH2O multilayers, which desorb completely upon heating to 120 K. After smaller exposures at low temperatures (45–65 K), STM allowed us to identify individual, isolated CH2O monomers. The theoretical results indicate that these monomers are bound to the surface Ti5c sites via σ-donation and adopt a tilted geometry. Upon heating, the CH2O monomers polymerize to form paraformaldehyde (polyoxymethylene, POM) chains, oriented primarily along the Ti5c rows ([001] direction). Upon further heating, POM is found to decompose around 250 K, releasing CH2O i...

PM3 and DFT Computational Studies of the Reaction Mechanism of Formaldehyde and Isoleucine

The reaction of formaldehyde and Isoleucine was studied using semi-empirical and density functional theory methods. Possible reactive sites are proposed and reaction mechanism postulated. It was found that the Isoleucine nitrogen attacks the carbonyl carbon of formaldehyde and forms a methylol intermediate that undergoes a condensation with another Isoleucine to produce a Methylenediisoleucine through a methylene bridge (cross-linking). The enthalpies of the reaction are -78.79 kJ/mol and -39.14kJ/mol for PM3 and DFT respectively also ΔSo and ΔGo, for the PM3 and DFT studies predicted. The reaction was found to be exothermic and second order.

Sulfonated porous carbon catalysts for biodiesel production: Clear effect of the carbon particle size on the catalyst synthesis and properties

Sulfonated porous carbons (PCs-SO3H) are prepared by the sol-gel reaction of resorcinol and formaldehyde. The porosity is maintained during drying using a cationic polyelectrolyte as pore stabilizer. It was found that varying the Resorcinol/Na2CO3 molar rate, different resins are produced which, after pyrolysis, give carbonaceous materials with different textural properties. It seems that a Resorcinol/Na2CO3 molar ratio of 200:1 was the optimal condition to produce a well-developed porous structure. Both resins and carbon materials are sulfonated by treatment with sulphuric acid. The relation between the carbon particles size, the sulfonation efficiency and its performance as a catalyst is studied. The higher amount of sulfonic groups, and thermal stability, as well as better catalytic performance, was obtained when smaller porous carbon particles were chosen by sieving. PCs-SO3H exhibited high efficiency for the esterification reaction and high performance for biodiesel production. The catalysts can be recycled several times with a minimal loss of activity. Thermal analysis evidenced stability up to ca. 200°C, allowing the use of this catalyst at high temperature. The simple synthesis and low cost of the PCs-SO3Hs make them promising catalysts for the synthesis of biodiesel.

Aerogel–aerogel composites for normal temperature range thermal insulations

Aerogel–aerogel composites are prepared by embedding highly insulating granular silica aerogel (1–2mm, 5–58vol.%) into ambient pressure dried resorcinol-formaldehyde (RF) aerogel. The organic RF aerogel matrix is synthesized via a sol–gel reaction of resorcinol (1,3-dihydroxybenzene) and formaldehyde in deionized water with Na2CO3 as the catalyst. Plates around 90×195mm² with a thickness of 19–25 mm are obtained and can be processed for application by sawing and grinding. A theoretical model for the volume-based surface area was used to show that the matrix aerogel around the silica aerogel grains is affected by their presence. Composites have a density 0.19≤ρ≤0.27g/cm³ and a thermal conductivity at room temperature between 0.026 and 0.053W/mK. Composites can be used as thermal insulation material in a normal temperature range<200°C due to the decomposition of the organic phase above 200°C.

Green and facile synthesis of dihydropyrrol-2-ones and highly substituted piperidines using ethylenediammonium diformate (EDDF) as a reusable catalyst

Extremely facile and efficient procedures have been developed for the synthesis of dihydropyrrol-2-ones and highly substituted piperidines. One-pot four-component reaction of amines, dialkyl acetylenedicarboxylates, and formaldehyde in the presence of ethylenediammonium diformate in ethanol under reflux conditions provides N-aryl-3-amino dihydropyrrol-2-one-4-carboxylates in good to high yields. The same conditions were found useful for the synthesis of highly substituted piperidines via a three (pseudo five)-component reaction of amines, aldehydes, and β-ketoesters. It is found that the catalyst is reusable and can be used up to five times without significant loss of its activity.

ChemInform Abstract: Nano‐TiCl4/SiO2: An Efficient Catalyst for the One‐Pot Synthesis of Highly Substituted Dihydro‐2‐oxopyrroles.

AbstractThe title pyrroles are efficiently obtained by one‐pot four‐component cascade reaction of various anilines, formaldehyde, and dialkyl acetylenedicarboxylates.

Synthesis and Characterization of 1-octyl 2-cyano Acrylate for Wound Healing Applications

Cyanoacrylate glues are quick setting materials which rapidly cure to hard, clear glassy resins. Its synthesis too has not been reported in the open literature so far. Synthetic methods, which engage esterification of cyanoacetic acid with a preferred alcohol, polymerization by knoevenagel condensation and successive depolymerization, are applied to the synthesis of lower membered alkyl cyanoacryaltes in which the alkyl groups carry less than 8 carbons. We have synthesized 1-octyl cyanoacetate by a traditional method involving p-toluene sulphonic acid as the catalyst. In the second step, we have attempted the preparation of poly (n-octyl cyanoacrylate) by the reaction of formaldehyde with n-octyl-2-cyanoacetate in the presence of both piperidine and potassium carbonate in the absence of any solvents. Its FTIR spectrum confirmed its functional groups: Its –OH stretching yielded a broad band around 3400 cm-1. The polymer was depolymerized using poly phosphoric acid catalyst under vacuum to obtain the monomer. A simple method of obtaining monomer was also attempted by the reaction of 1-octyl- 2-cyano acetate and diiodomethane in the presence of potassium carbonate. This process directly yields the monomer. The second method looks better than the others, and it can be applied to any type of alcohols.

Prediction of the vapor–liquid equilibrium of chemical reactive systems containing formaldehyde using the COSMO-RS method

We herein present a quantum chemical method for predicting the thermodynamic properties of a reactive formaldehyde + water system. The TURBOMOLE program was used to obtain the σ profiles of poly(oxymethylene) glycol oligomers produced via a series of chemical reactions in aqueous solution. The conductor-like screening model for real solutions (COSMO-RS) method, in combination with chemical equilibrium constants and the mass balance equation obtained using MATLAB, was successfully used to calculate the activity coefficients of all compounds in the liquid. Based on NMR data from the literature along with the obtained activity coefficients, we modified the thermodynamic chemical equilibrium constant Kn∗ for glycol formation. Finally, we estimated the vapor–liquid equilibrium and distribution of oligomers (MGn, n ≥ 1) in the formaldehyde-water solution. The COSMO-RS method was thus proven to be an efficient tool to study formaldehyde-containing aqueous solutions, and can be used as a basis for other similar reactive systems.

芳香醛、芳香酮和芳香胺的Mannich反应研究概况

芳香醛、芳香酮和芳香胺参与的Mannich反应，其合成方法和甲醛参与的Mannich反应差别较大，生成的某些Mannich碱显示多方面的生物活性，包括抗糖尿病、抗肿瘤、抗微生物和抗结核等活性。本文主要总结和讨论此类Mannich反应的发展历程及曼尼碱的生物活性，希望对相关研究人员有一定的参考价值。 The Mannich reaction of aromatic aldehydes, aromatic ketones with aromatic amines has re-markable difference in synthetic method compared with that of Mannich reaction of formaldehyde. Some Mannich bases exhibit specific biological activity, such as antidiabetic, antimicrobial, anti-tumor, and anti-tuberculosis activity. This paper primarily summarizes the development history of this kind of Mannich reaction and further introduces their biological activities mainly discovered by our lab, and hope to provide hint for future investigation of this Mannich reaction.

Bis-amino methylation for the synthesis of spiro-fused piperidines using iron(III) trifluroacetate in aqueous micellar medium

An environmentally benign, multicomponent integrated chemical process has been developed for the synthesis of 3,5-dispirosubstituted piperidines by cyclo-condensation reaction of amines, formaldehyde, and dimedone using iron(III) trifluroacetate [Fe(F3CCO2)3] Lewis acid in aqueous micellar medium at ambient temperature (25–30 °C). The heterogeneous solid acid catalyst conveniently promotes this double amino methylation reaction in which six molecules condense in one pot to form six new covalent bonds. The synthesized 3,5-dispirosubstituted piperidines have been screened for their in vitro antibacterial activity using agar well method. Many of these compounds showed satisfactory antibacterial activity as compared to standard drugs against all the bacteria tested.

Preparation and Characterization of Novel Polyaniline Nanosensor for Sensitive Detection of Formaldehyde.

Nanomaterials are promising in the field of optical sensors due to their unique properties. Emeraldine base of polyaniline (Nano EB-PANI) was prepared, characterized and applied as an optical formaldehyde sensor. FTIR data confirm the formation of the EB-PANI. TEM and SEM revealed the size and shape of the nanoscale EB-PANI. XRD showed that the obtained nano EB-PANI has a partial crystalline nature. The sensing mechanism is based on the reaction of formaldehyde with Nano EB-PANI- to form a complex as described by molecular modeling HF/3-21G** level of theory. Results showed that Nano EB-PANI- detect low concentrations of formaldehyde ranging from 0.0003 to 0.9 ppm in a dose-dependent manner. The molecular modeling theory analysis showed that formaldehyde could interact with the amine of EB-PANI in, ring 3 or 4 or both together. The binding energy and dipole moment of the interaction between formaldehyde and polyaniline nanosensor were calculated by HF/3-21g** level of theory. The interaction with ring 3-NH gives a less stable product with a high dipole moment 6.978 Debye comparing with 1.678 Debye for the product of formaldehyde interaction with the terminal ring 4-NH. The development of such novel EB-PANI nanosensor can be used as, reliable and sensitive formaldehyde sensor.

FORMALDEHYDE REMOVAL FROM WASTEWATER APPLYING NATURAL ZEOLITE / FORMALDEHIDO ŠALINIMAS IŠ NUOTEKŲ PANAUDOJANT GAMTINĮ CEOLITĄ

Formaldehyde is one of the most chemically active compounds which is discharged with untreated or just partially treated industrial wastewater. It is hazardous for environment and humans. Formaldehyde vapors can strongly irritate skin, can cause damage to eyes and harm respiratory tract. As long as formaldehyde causes a toxic effect on environment and living organisms, it is necessary to remove it from wastewater which is directed to natural water. There are many methods used for formaldehyde removal from wastewater: biological method, evaporation, membrane separation method. Most of them have disadvantages. Adsorption method has many advantages: it is fast, cheap, and universal, and can be widely used, therefore it was chosen for this research. Experiment was carried out with natural zeolite in different contact time with different concentration formaldehyde solutions. Concentration of formaldehyde was determined applying the Photocolorimetric Method. Method is based on reaction of formaldehyde with chromotropic acid and determination of formaldehyde concentration. Determined average sorption efficiency was highest when formaldehyde concentration was lowest, e. g. 2 mg/l (45.94%) after eight hours of contact time with adsorbent. Sorption efficiency was increasing when the contact time increased, but when the contact time increased to 12 hours, sorption efficiency stayed the same because of the saturation of zeolite. Formaldehidas yra vienas iš aktyviausių junginių, kuris išleidžiamas į aplinką kartu su nevalytomis ar iš dalies išvalytomis gamybinėmis nuotekomis. Jis yra pavojingas tiek aplinkai, tiek žmonėms. Formaldehido garai stipriai dirgina akis ir kvėpavimo sistemą. Kadangi formaldehidas yra pavojingas žmonėms ir visiems gyviems organizmams, jis turi būti šalinamas iš gamybinių nuotekų. Sorbcijos metodas turi daug privalumų: jis yra greitas, pigus ir universalus, todėl vienas iš labiausiai perspektyvių vandens valymo metodų – sorbcija. Tai pagrindinė priežastis, kodėl sorbcinis metodas buvo pasirinktas eksperimentiniams tyrimams. Eksperimentiniai tyrimai buvo atlikti naudojat gamtinį ceolitą, buvo parinktas skirtingas formaldehido tirpalo kontakto laikas su adsorbentu ir matuojama teršalų koncentracija po kontakto su adsorbentu. Šis metodas yra paremtas formaldehido reakcija su chromotropine rūgštimi. Sorbcijos efektyvumas augo ilgėjant kontakto su ceolitu laikui, tačiau po 12 valandų efektyvumas nebedidėjo dėl to, kad sorbentas įsisotino.

Nano Fe3O4 as a magnetically recyclable, powerful, and stable catalyst for the multi-component synthesis of highly functionalized dihydro-2-oxopyrroles

A mild and efficient method for the one-pot synthesis of functionalized dihydro-2-oxopyrroles is described via four-component domino reaction of amines, dialkyl acetylenedicarboxylates, and formaldehyde in the presence of super magnetic nano iron oxide (nano Fe3O4) in EtOH at room temperature. The major advantages of the present method are mild and green reaction conditions, high yields, short reaction times, clean reaction, magnetically recyclable catalyst, atom economy (63–76 %), operational simplicity, and no need for column chromatography. It is found that the catalyst is recyclable and can be used up to six times without significant loss of its activity.