2127-14-2

Basic information

• Product Name: (1-methylpyridin-4(1H)-ylidene)-N-oxomethanaminium
• CAS NO: 2127-14-2
• Molecular Formula: C₇H₉N₂O*I
• Molecular Weight: 137.1586
• Mol File: 2127-14-2.mol

Chemical Properties

• Boiling Point: 187.7°C at 760 mmHg
• Flash Point: 67.3°C
• Vapor Pressure: 0.621mmHg at 25°C
• CAS DataBase Reference: (1-methylpyridin-4(1H)-ylidene)-N-oxomethanaminium(CAS DataBase Reference)
• NIST Chemistry Reference: (1-methylpyridin-4(1H)-ylidene)-N-oxomethanaminium(2127-14-2)
• EPA Substance Registry System: (1-methylpyridin-4(1H)-ylidene)-N-oxomethanaminium(2127-14-2)

Safety Data

• Hazardous Substances Data: 2127-14-2(Hazardous Substances Data)

Usage

Uses

Used in Pharmaceutical Synthesis:
Meldrum's acid is used as a precursor in the synthesis of various pharmaceutical compounds, contributing to the development of new medications and therapies.
Used in Agrochemical Production:
It is also utilized in the production of agrochemicals, playing a role in the creation of substances that help protect and enhance crop yields.
Used in Organic Synthesis:
Meldrum's acid serves as a versatile nucleophilic reagent in organic synthesis, enabling the introduction of a wide range of functional groups to other molecules.
Used in Materials Science:
In the field of materials science, Meldrum's acid is used in the synthesis of polymers and nanoparticles, contributing to the advancement of new materials with diverse applications.
Used in Research and Development:
Meldrum's acid is employed in research and development settings to explore its potential applications and to innovate new methods for its utilization in various industries.

Upstream product

• 696-54-8 pyridine-4-aldoxime 
• 74-88-4 methyl iodide 
• 872-85-5 pyridine-4-carbaldehyde 
• 1637-52-1 4-pyridinealdoxime 

Downstream Products

• 14609-74-6 p-nitrophenolate 
• 58822-12-1 4-pyridinealdoxime methchloride 
• 57092-56-5 C₉H₁₁N₂O₂⁽¹⁺⁾*I^(1-) 

Relevant articles and documents

QUATERNARY HETEROARENIUM ALDOXIMES AS CATALYSTS FOR CLEAVAGE OF PHOSPHATE ESTERS

!-Methyl- (Ia - Id) and 1-dodecyl-2-, 3- and 4-hydroxyiminomethylpyridinium salts (Ie - Ih), as well as 1-methyl- (IIa) and 1-dodecyl-3-hydroxyiminomethylpyridazinium salts (IIb, IIc), were synthesized as catalysts for hydrolytic cleavage of organophosphates.The activities of the prepared catalysts were evaluated by measuring rate constants of hydrolysis of 4-nitrophenyl diphenyl phosphate (PNPDPP) under conditions of a pseudo-first-order reaction.The observed reactivity of pyridinium aldoximes Ia - Ih towards PNPDPP in neutral or slightly basic aqueous solutions (pH 7.2 and 7.8) depends on the acidity of the hydroxyimino group.The cleavage of PNPDPP is strongly accelerated in solutions of 1-dodecylhydroxyiminomethylpyridinium salts Ie - Ih above their critical micellar concentration (CMC).Considerable effect on the velocity of PNPDPP cleavage was observed when quaternary pyridinium aldoximes Ie - Ih were comicellized with inert cationic tenside hexadecyltrimethylammonium bromide (CTAB). 1-Dodecyl-3-hydroxyiminomethylpyridazinium salts IIb and IIc were unstabel in aqueous solutions under the above-mentioned conditions.

Carbon-13 NMR Characterization of the Bispyridinium Oximes, Toxogonin, HS-3, HS-6 and HI-6

The structure of the bispyridinium oximes, toxogonin, HS-3, HS-6 and HI-6, used as antidotes in organophosphorus poisoning, is confirmed by 13C NMR spectroscopy.The 13C NMR spectra of the corresponding monopyridinium precursors substantiate the signal assignment in the bispyridinium oxime spectra.In all oximes studied the hydroxyiminomethyl group (-CH=N-OH) exists in the syn configuration.The 13C signal differences also readily allow analysis of binary mixtures of the oximes and provide an easy method for monitoring their stability.

Synthesis of 1,2,5,6-/1,2,3,6-Tetrahydropyridinyl-tetrahydrocyclopentaisoxazole Derivatives

Fused tetrahydrocyclopenta-isoxazoles were synthesized by 1,3-dipolar cycloaddition reactions with pyridinealdoxime or tetrahydropyridinealdoxime and cycloalkenes.

Microwave-assisted quaternization of various pyridine derivatives and their antibacterial activity

In this study, reactions of quaternization under microwave heating of pyridine, α-picoline, pyridine-4-aldoxime, pyridine-2-aldoxime, nicotinamide, isonicotinamide and pyridoxal oxime with different electrophiles: 2-bromo-4'-nitroacetophenone, 2-amino-4-chloro-methylthiazole hydrochloride, methyl iodide, 1, 3-diiodopropane and 1, 3-dibromopropane are reported. The synthesis yield by microwave dielectric heating is improved and reaction time shortened compared to conventional heating. The structure of obtained molecules were analyzed and determined by 1D and 2D NMR spectroscopy methods, IR spectroscopy and mass spectrometry. The highest antibacterial activity against two Gram-positive and two Gram-negative bacteria strains has been found for 1-[2-(4-nitrophenyl)-2-oxoethyl]pyridinium bromide (2).

Spectroscopic and structural insights into N-substituted pyridinium-4-aldoximes and their pentacyanoferrate(II) complexes

Comparative kinetic and equilibrium studies on the formation and dissociation of three mono- and one bis-pyridinium-4-aldoxime pentacyanoferrate(II) complexes have been carried out in aqueous solutions at 25 °C and I = 0.1 M. The synthesis, spectroscopic and thermal characterization of a new N-methylpyridinium-4-aldoxime pentacyanoferrate(II) complex is presented. The obtained values for the equilibrium constants, identified as apparent formation constants (βf/M-1) along with kinetic parameters, the formation (kf/M-1 s-1) and dissociation (kd/s-1) rate constants indicated the behaving of all protonated pyridinium-4-aldoximes as weak π-acceptors. The pH-dependence of the dissociation rates has been analyzed in terms of ionization abilities of the coordinated ligands. The magnitude of the dissociation rates suggested that both protonated and deprotonated ligand forms are effective σ-donors that bind to the [Fe(CN)5]3- moiety through the nitrogen atom. The deprotonation of the coordinated aldoxime group leads to the reduced lability of the complexes due to increased σ-donor capability of aldoximato nitrogen causing the strengthened of the iron(II)-nitrogen bond. The values of dissociation activation parameters, ΔH? and ΔS?, are found to be consistent with the S N1 dissociative type of mechanism. The spectroscopic data (FT-IR, NMR and UV-Vis) of the isolated coordinated pentacyanoferrates(II) conforms with the weak π-acceptor properties of the pyridinium-4-aldoxime ligands. A detailed structural characterization of the iodide and chloride salt of N-methylpyridinium-4-aldoxime was also presented using NMR, FT-IR and UV-Vis spectroscopy, as well as X-ray diffraction.

Hydrolysis of carboxylate and phosphate esters using monopyridinium oximes in cationic micellar media

The reactions of p-nitrophenyl acetate (PNPA) with a series of monopyridinium oximes, viz. 2-PAM (2-hydroxyiminomethyl-1-methylpyridinium iodide), 3-PAM (3-hydroxyiminomethyl-1-methylpyridinium iodide), and 4-PAM (4-hydroxyiminomethyl-1-methylpyridinium iodide) have been studied in the presence of cationic surfactants of same hydrophobic chain length (C 16) within the concentration range of 0.5-6.0 mM at pH 8.0 under the pseudo-first-order condition. The observed rate constant (kobs) increases with increasing surfactant concentration culminating into a maximum, and this has been analyzed in detail following the concepts of micellar catalysis. The structure-activity relationship of the investigated oximes has been discussed, and 2-PAM was found to be the most reactive among all the three investigated oximes for the cleavage of PNPA. Esterolytic decomposition of p-nitrophenyldiphenyl phosphate with oximate ions (-CH=NO-) was followed in cetyltrimethylammonium bromide micelles at pH 9.0, and 4-PAM was the most reactive oxime for the micellar hydrolysis of phosphate ester. The apparent acid dissociation constants (pKa) of the investigated oximes have been determined spectrophotometrically.

Preparation and in vitro evaluation of monoquaternary inhibitors of brain cholinesterases

Acetylcholinesterase inhibitors are currently of high interest due to the many reasons. Among them, Alzheimer's disease drugs are of great interest. In this study, eleven monoquaternary pyridinium salts substituted by different groups (electron donors and

Monoquaternary pyridinium salts with modified side chain-synthesis and evaluation on model of tabun- and paraoxon-inhibited acetylcholinesterase

Acetylcholinesterase reactivators are crucial antidotes for the treatment of organophosphate intoxication. Eighteen monoquaternary reactivators of acetylcholinesterase with modified side chain were developed in an effort to extend the properties of pralidoxime. The known reactivators (pralidoxime, HI-6, obidoxime, trimedoxime, methoxime) and the prepared compounds were tested in vitro on a model of tabun- and paraoxon-inhibited AChE. Monoquaternary reactivators were not able to exceed the best known compounds for tabun poisoning, but some of them did show reactivation better or comparable with pralidoxime for paraoxon poisoning. However, extensive differences were found by a SAR study for various side chains on the non-oxime part of the reactivator molecule.