Use Of Nitromethane Research Articles

Experimental and Computational Studies of Microwave-Assisted, Facile Ring Opening of Epoxide with Less Reactive Aromatic Amines in Nitromethane.

Nucleophilic ring opening reactions of epoxides with aromatic amines are in the forefront of the synthetic organic chemistry research to build new bioactive scaffolds. Here, convenient, green, and highly efficient regioselective ring opening reactions of sterically hindered (2R,3S)-3-(N-Boc-amino)-1-oxirane-4-phenylbutane with various poorly reactive aromatic amines are accomplished under microwave irradiation in nitromethane. All the reactions effectively implemented for various aromatic amines involve the reuse of nitromethane that supports its dual role as a solvent and catalyst. The corresponding new β-alcohol analogs of hydroxyethylamine (HEA) are isolated in 41–98% yields. The reactions proceed under mild conditions for a broad range of less reactive and sterically hindered aromatic amines. Proton NMR experiments suggest that the nucleophilicity of amines is influenced by nitromethane, which is substantiated by the extensive computational studies. Overall, this methodology elucidates the first-time use of nitromethane as a solvent for the ring opening reactions under microwave conditions involving an equimolar ratio of epoxide and aromatic amine without any catalyst, facile ring opening of complex epoxide by less reactive aromatic amines, low reaction time, less energy consumption, recycling of the solvent, and simple workup procedures.

Sc(OTf)3-Catalyzed Synthesis of Symmetrical Dithioacetals and Bisarylmethanes Using Nitromethane as a Methylene Source.

Use of nitromethane as an electrophilic methylene source for the synthesis of symmetrical dithioacetals and bisarylmethanes has been showcased using Sc(OTf)3 as a catalyst. The procedure allows straightforward access to the densely functionalized dithioacetals and bisarylmethanes under mild conditions. Additionally, the method has been applied for the synthesis of antimalarial tetramethyl mellotojaponin C and anticancer dimeric phloroglucinol derivative.

Nitromethane as a surrogate cyanating agent: 7-N,N-dimethylamino-4-hydroxycoumarin-catalyzed, metal-free synthesis of α-iminonitriles

An alkali and cyanide free approach for the synthesis of α-iminonitriles via a base-mediated and 1,3-diketone-catalyzed reaction is reported. The preparation of target compounds was realized by use of nitromethane as solvent and cyanating agent, offering a greener process.

(Invited) A Simple and Efficient Solution-Based Technique to Electrically Dope Organic Semiconductors

The printed electronics industry offers a paradigm change in manufacturing, cost and environmental impact when compared to the conventional semiconductor industry. Printed electronic devices are expected to be mass-produced from less-energy-demanding processes over large areas and on flexible substrates, with techniques that closely resemble the well-known mass production of printed media on paper. Still, critical to the widespread of these devices is the ability to convert lab produced “champion” figures into reliable industrial-scale products. The well-established strategies for the design and fabrication of efficient lab-scale printed electronics are not always compatible with large-area manufacturing, where several additional requirements must be met. Solution-based electrical doping of organic semiconductors has received increased attention as a technique with the potential to comply with some of these additional requirements. Stable ink-type formulations of dopant, semiconductor and solvents have been reported, some of which may be compatible with roll-to-roll coating. Yet, the ability to fabricate vertical doping gradients, critical to maintain optimal optoelectronic performance at reduced cost, has proven challenging. Vertical doping gradients would reduce the amount of coating steps without a loss in optoelectronic device functionality, simplifying manufacturing and preventing defects to propagate. In 2017 we reported a simple technique to fabricate vertical electrical p-type doping gradients in organic semiconductor films by dipping them in solutions. Still, the initial approach, which involved 12-molybdophosphoric acid (‘PMA’ dopant) and nitromethane (processing solvent), was highly solvent selective, and the use of nitromethane was found limiting. Thus, in 2018, our team replaced nitromethane with acetonitrile and showed that the PMA-acetonitrile solution became stable in air without losing its doping ability. Furthermore, organic solar cells fabricated using the updated approach showed longer air stability. In this talk we will start by discussing the basics of the solution-based technique to electrically p-type organic semiconductors using PMA, and compare it against similar, well-studied approaches. Then, we will emphasize on our latest insights on the path to unravel, from a molecular perspective, how organic semiconductors are doped down to a limited depth from solution, using PMA molecules. That is, what is the interplay between the organic film and PMA molecules in solution that leads to p-type electrical doping of the semiconducting layer? Additionally, what are the key parameters that determine the efficiency and extent of the process?

Safe Use of Nitromethane for Aldol Reactions in Flow

Using a simple flow reactor, the safe use of nitromethane at elevated reaction temperatures was demonstrated in a nitroaldol reaction of different aldehydes. The reaction products were isolated in good yields after a short reaction time

Chiral Radical‐Cation Salts of BEDT‐TTF Containing a Single Enantiomer of Tris(oxalato)aluminate(III) and ‐chromate(III)

AbstractRadical‐cation salts of BEDT‐TTF with chiral anions provide the opportunity to combine chirality with conductivity in the same molecular material. We report here two salts, (BEDT‐TTF)3NaAl(C2O4)3·nitromethane and (BEDT‐TTF)3(NH4)0.83Cr1.17(C2O4)3·nitromethane. The former crystallises in space group P21 and the latter in P212121. The use of nitromethane alone as the electrolyte for electrocrystallisation produces no crystals, but the addition of chiral (R)‐(–)‐carvone yields crystals of these two new chiral radical‐cation salts of BEDT‐TTF through chiral induction from racemic tris(oxalato)aluminate(III) and tris(oxalato)chromate starting materials. The honeycomb anion layers in these salts contain a single enantiomer of tris(oxalato)metallate and creates hexagonal cavities that are smaller than those found in the superconducting β″ salts in this tris(oxalate)metallate family, which gives preference for smaller solvents to be included, such as nitromethane. The chromium salt has a non‐stoichiometric composition of the anion layer, which provides an electron doping effect to the donor layer.

ChemInform Abstract: Zinc‐Catalyzed Direct Cyanation of Indoles and Pyrroles: Nitromethane as a Source of a Cyano Group.

AbstractThe use of nitromethane as CN‐source for the direct cyanation of indoles and pyrroles is demonstrated.

AN IMPROVED LIQUID SCINTILLATION COUNTING METHOD FOR THE DETERMINATION OF GROSS ALPHA ACTIVITY IN GROUNDWATER WELLS

A liquid scintillation counting (LSC) method having several advantages over the gas proportional counting (GPC) U.S. Environmental Protection Agency (EPA) Method 900.0 for the detection of gross alpha activity in drinking water was evaluated in this study. The improved method described here involves the use of nitromethane as the quench agent for establishing counting efficiencies and spillover factors, and it minimizes sample preparation. It has the advantage of achieving the regulatory detection limit of 111 mBq L(-1) with short count times (100 min) and small sample aliquot sizes. A thorough method validation study was performed by testing field samples ranging in total dissolved solids (TDS) from 0.3 mg L(-1) to 1,000 mg L(-1) and spiking each matrix from 194 mBq L(-1) to 11.6 Bq L(-1). Comparable method precision and accuracy was observed on the two types of LSC instruments tested, Perkin Elmer Quantulus 1220 and Packard 2550, with the former giving better performance. Data presented demonstrate that this efficient and high throughput LSC method is suitable for groundwater samples in excess of 1,000 mg L(-1) of TDS in contrast with the 500 mg L(-1) limit by the routine GPC method. Groundwater wells across the state of California were sampled, analyzed for gross alpha activity using the EPA- approved method and the improved LSC method, and the results were compared.

Reactions of 2-(2-propynylsulfanyl)-5,6,7,8-tetrahydrobenzo[b]thieno[2,3-d]pyrimidin-4(3H)-one with arylsulfenyl chlorides

2-(2-propynylsulfanyl)-5,6,7,8-tetrahydrobenzo[b]thieno[2,3-d]pyrimidin-4(3H)-one with arylsulfenyl chlorides in chloroform gave products of anti-Markownikoff Ad E-addition. The use of nitromethane as solvent in the presence of lithium perchlorate additives favored intramolecular electrophilic cyclization into 1-arylsulfanyl-1,2,6,7,8,9-hexahydro-4H-benzo[4,5]thieno[3,2-e][1,3]thiazolo[3,2-a]-pyrimidin-5-one.

Cyclopropanation of Olefins with Nitromethane

A procedure for the use of nitromethane as an iodonium ylide precursor has been developed. Electron-rich olefins are cyclopropanated with nitromethane in the presence of bis(acetoxy)iodobenzene, a base and a Rh(II) catalyst to provide nitrocyclopropanes in moderate to good yields.

Preparation of β-nitroalanine using the Easton three-component coupling method

A simple one-step preparation of beta-nitroalanine has been developed using the Easton three-component coupling method. To date one limitation of this method has been that use of nitromethane as the nitroalkane component does not yield beta-nitroalanine. We report that use of the dipotassium salt of nitroacetic acid in the Easton three-component coupling gives beta-nitroalanine in high yield, presumably via facile decarboxylation of a beta-nitroaspartate intermediate.

Characterization of basic catalysts by the use of nitromethane as NMR probe molecule and reactant

Characterization of the basicity of mixed oxides obtained from hydrotalcite-like precursors by 13C CP/MAS NMR spectroscopy using nitromethane-reactive adsorption is described. On Lewis bases, featuring acid–base pairs, the nature of adsorbed species namely nitromethane, aci-anion nitromethane, and methazonate salt analogue depends on the relative strength of the basic and acid sites on the pairs. None of these species is obtained using Brønsted bases such as layered double hydroxide (LDH) of the meixnerite type. In that case a formate analogue is proposed to be formed. Heterogeneous base catalysis of the Michael addition of nitromethane to cyclohex-2-en-1-one is studied. A relationship is established between the activity of the catalyst and the 13C CP/MAS NMR chemical shift of the aci-anion nitromethane which is a measure of the basic strength. Discussion of NMR and catalytic results takes into account the respective roles of basicity and of conjugate Lewis acidity. Basicity is needed to form a reactive anion comparable to aci-anion nitromethane, but the higher the stabilization of aci-anion nitromethane by Lewis acidity, the lower the activity. Increasing the basic strength by decreasing the Lewis acidity of the acid–base pairs leads to an increase of activity concomitant with the formation of methazonate as shown by 13C MAS NMR. The efficiency of meixnerite which is the most active and selective catalyst is related not only to its Brønsted basicity but also to its weak Lewis acidity.

Heterogenation of water-sensitive organometallic catalysts into layered aluminosilicates

Non-aqueous intercalation of montmorillonite with the water-sensitive species [Mn 3O(CH 3COO) 6pyr 3] was achieved with the use of nitromethane as solvent. The adsorption of the complex into the clay was studied photometrically and follows second order kinetics. Thermogravimetric analysis showed that the complex is adsorbed in excess of the CEC of the clay. XRD measurements suggest that the complex is intercalated parallel to the sheets. The surface area of the fired solids is rather low, due the small height of the formed MnO x pillars.

The Ionic Telomerization of Conjugated Diene Compounds. II. The Solvent Effects on the Cationic Telomerization of Butadiene with Its Hydrochloride

Abstract The telomerizations of butadiene with its hydrochlorides (1-chlorobutene-2 and 3-chlorobutene-1) in several sorts of solvents in the presence of Lewis acids were investigated. Titanium tetrachloride in ethyl bromide has a considerable catalytic ability at low temperatures and gives telomers with higher average molecular weights than ferric chloride and aluminum chloride at almost the same conversions of reaction. On the other hand, antimony pentachloride gives only a small amount of product with lower average molecular weights. The telomerizations in methylene dichloride and chloroform give almost the same amounts of telomers with molecular weights higher somewhat in the former solvent than the latter. The telomerization in toluene gives primarily the products of Friedel-Crafts reaction, and a small amount of telomers of butadiene with crotyl chloride is obtained. The use of ethyl ether, acetonitrile and acetic anhydride as solvents at low temperatures in the presence of ferric chloride affords poor yields of the telomers in contrast to the cases of halogenated hydrocarbons. In ethyl ether, an appreciable amount of telomers is obtained only at the temperatures above 0°C. The telomers thus obtained have a lower average molecular weight and a larger degree of residual unsaturation than the telomers obtained in halogenated hydrocarbons. The use of nitromethane and nitrobenzene as solvents leads to the formation of an amount of telomers smaller a little than halogenated hydrocarbons. There are scarcely observed differences in the compositions of fractions in 1 : 1 adducts of butadiene and its hydrochloride obtained in the various solvents. The infrared spectra of the higher telomers are almost the same each other and it was concluded that the reactions proceed on the same mechanism irrespective of the variation of solvents.

A New Method for the Determination of Nitrofurantoin in Urine

Abstract Nitrofurantoin is presently used as an antibacterial agent for the urinary tract of both man and animals. A new, quantitative procedure for the determination of this drug in urine consists of direct extraction of the nonionized form of the drug by the use of nitromethane, addition of an alkaline reagent to the extract to produce a visible color, and determination of the nitrofurantoin concentration by spectrophotometry. The method has a sensitivity of 5 mg./L., with recoveries of 99-101% and a standard curve that is linear to 100 mg./L. Results indicate that the method measures nitrofurantoin alone, and not its metabolites, in rat, dog, and human urine.

Rǒle of rate of decomposition of nitric oxide in the use of nitromethane as a monopropellant

AbstractThe high value of L* necessary for stable combustion of nitromethane in a rocket motor is attributed to the rate of reaction of nitric oxide with fuel molecules. Addition of metallic cations which catalyse the oxidation reactions or decomposition of nitric oxide reduce the L* necessary for sustained combustion.

R??le of rate of decomposition of nitric oxide in the use of nitromethane as a monopropellant

R??le of rate of decomposition of nitric oxide in the use of nitromethane as a monopropellant