130160-97-3

Upstream product

• 43067-01-2 3,5-bis(methoxycarbonyl)-4-(2-chlorophenyl)-2,6-dimethyl-1,4-dihydropyridine 
• 89-98-5 2-chloro-benzaldehyde 
• 105-45-3 acetoacetic acid methyl ester 
• 552-89-6 2-nitro-benzaldehyde 

Downstream Products

• 97744-29-1 Methyl 2,4-dimethyl-5-oxo-5H-<1>benzopyrano<3,4-c>pyridine-1-carboxylate 

Relevant academic research and scientific papers

Study of temperature dependent three component dynamic covalent assembly VIa Hantzsch reaction catalyzed by dioxido- and oxidoperoxidomolybdenum(VI) complexes under solvent free conditions

Tridentate ONO donor ligands derived from heterocyclic compound 4-acetyl-3-methyl-1-phenyl-2-pyrazoline-5-one (Hap) and aromatic hydrazides {benzoyl hydrazide (Hbhz), isonicotinoyl hydrazide (Hinh), nicotinoyl hydrazide (Hnah) and furoyl hydrazide (Hfah)} react with [MoVIO2(acac)2] (Hacac = acetylacetone) in equimolar ratio in methanol to give dioxidomolybdenum(vi) complexes, [MoO2(ap-bhz)(MeOH)] 1, [MoO2(ap-inh)(MeOH)] 2, [MoO2(ap-nah)(MeOH)] 3 and [MoO2(ap-fah)(MeOH)] 4. Reaction of these ligands with in situ generated oxidoperoxidomolybdenum(vi) precursor results in the formation of oxidoperoxidomolybdenum(vi) complexes, [MoO(O2)(ap-bhz)(MeOH)] 5, MoO(O2)(ap-inh)(MeOH)] 6, MoO(O2)(ap-nah)(MeOH)] 7 and MoO(O2)(ap-fah)(MeOH)] 8. These complexes have been characterized by elemental analysis, spectroscopic techniques (infrared, UV-vis, 1H and 13C NMR) and thermogravemetric analysis. The structures of complexes [MoVIO2(ap-bhz)(H2O)] 1a (water coordinated), [MoVIO2(ap-bhz)(DMSO)] 1b (DMSO coordinated), [MoVIO2(ap-nah)(DMF)] 3a (DMF coordinated), [MoVIO(O2)(ap-bhz)(MeOH)] 5 (methanol coordinated) and [MoVIO(O2)(Hap-nah)(OMe)]·MeOH 7a (methoxy coordinated) have been confirmed by single crystal X-ray studies. X-ray diffraction study also reveals that tridentate ligands bind to the metal center through enolic oxygen (of pyrazolol), azomethine nitrogen and enolic oxygen (of hydrazide) atoms. In complex 7a, pyridinic nitrogen is protonated. These complexes [dioxidomolybdenum(vi) as well as oxidoperoxidomolybdenum(vi)] have been tested as catalysts for temperature dependent one pot three component (methylacetoacetate, benzaldehyde and ammonium acetate) dynamic covalent assembly, via Hantzsch reaction, using 30% H2O2 as a green oxidant under solvent free conditions. Various parameters such as the amount of catalyst, oxidant and temperature of the reaction mixture have been taken into consideration to optimize the reaction conditions. In the Hantzsch reaction, the temperature and oxidant control the conversion and selectivity of the desired product.

Remarkably fast and selective aromatization of Hantzsch esters with MoOCl4 and MoCl5: A chemical model for possible biologically relevant properties of molybdenum-containing enzymes

Mo(VI) and Mo(V) salts both react selectively with Hantzsch esters to produce substitute pyridines in good-to-excellent yield (75-99%). The remarkable reactivity and selectivity of MoOCl4 under reflux of acetonitrile and MoCl5 in dichloromethane at room temperature encouraged us to propose that molybdenum-containing enzymes (such as xanthine or aldehyde oxidase) also participate to some degree in the metabolism of 1,4-dihydropyridine drugs in the liver analogous to NADH in the respiratory chain.

Metal-Free oxidation of urazole and 1,4-dihydropyridine derivatives under mild and heterogeneous conditions by nitro urea, derived from urea nitrate, and silica sulfuric acid

Mild combination of nitro urea, derived from urea nitrate, and silica sulfuric acid (SiO2OSO3H) might act as an efficient oxidizing media, which could be able to oxidize different types of heterocyclic compounds including urazoles and 1,4-dihydropyridines. The process presented here is operationally simple, environmentally benign, and reactions have been mildly carried out in dichloromethane at room temperature.

Photochemistry of Hantzsch 1,4-dihydropyridines and pyridines

The photochemistry of some Hantzsch 4-phenyl-1,4-dihydropyridines bearing a substituent on the phenyl ring (the three isomeric chloro derivatives and the 4′-nitro derivative) has been studied. All of these compounds underwent inefficient aromatization to

A highly efficient biomimetic aromatization of Hantzsch-1,4-dihydropyridines with t-butylhydroperoxide, catalysed by iron(III) phthalocyanine chloride

Rapid aromatization of Hantzsch-1,4-DHPs with t-butylhydroperoxide catalysed by iron(III) phthalocyanine chloride is described. The reaction proceeds smoothly at room temperature within 1-35 min and the products of high purity were isolated in excellent yields. To explain the reactivity of this catalytical system plausible mechanism have been proposed to involve formation of high-valent oxoferryl species as in cytochrome P450 itself.

An efficient, metal-free, room temperature aromatization of Hantzsch-1,4-dihydropyridines with urea-hydrogen peroxide adduct, catalyzed by molecular iodine

A mild, highly efficient and metal-free synthetic method for aromatization of 1,4-dihydropyridines employing urea-hydrogen peroxide adduct as oxidant catalyzed by 20 mol % of molecular iodine was developed. The reaction was carried out in ethyl acetate at room temperature and the products were isolated in high to excellent yields. A plausible free-radical mechanism is proposed based on results obtained with derivatives having alkyl and aryl substituents in the 1,4-dihydropyridine ring.

Rapid, efficient, room temperature aromatization of Hantzsch-1,4-dihydropyridines with vanadium(V) salts: superiority of classical technique versus microwave promoted reaction

The aromatization of 1,4-dihydropyridines (1,4-DHPs) employing group 4 (Zr and Hf) and 5 (V, Nb, Ta) elements of periodic system has been studied. The reaction with VOCl3 in dichloromethane at room temperature afforded products, substituted pyridines, in high-to-excellent yield. For the first time, the formation of charge-transfer complexes (CTCs) has been evidenced in preorganization step between 1,4-DHP and oxidant before electron transfer. The CTC has been formed only in neutral solvents such as dichloromethane and is characterized by intensive coloration. The aromatization of 1,4-DHP with V2O5 in refluxing acetic acid has found to be superior over microwave promoted reaction in solventless media. The only reasonable explanation was found in polymeric structure of V2O5, which slowly transfer energy of microwaves needed for the activation of the reactants. The solvent polarity dependent oxidative dealkylation of 4-n-propyl-1,4-DHP has been discovered. Unexpectedly, the reaction in acetic acid afforded only 33% of dealkylated product compared to 91% obtained in dichloromethane under the same reaction conditions.

A facile aromatisation of 1,4-dihydropyridines by ammonium nitrate in acetic acid

The oxidation of 1,4-dihydropyridines to pyridines with ammonium nitrate as an oxidant in the presence of acetic acid proceeds in excellent yield.

Oxidative-aromatization of Hantzsch ester 1,4-dihydropyridines by KBrO 3/SnCl4-5H2O under mild condition

Different kinds of Hantzsch ester 1,4-dihydropyridines were oxidatively aromatized to their corresponding pyridine derivatives by KBrO 3/SnCl4 · 5H2O system in refluxing CH3CN. The products were obtained in high to excellent yields.

Aromatization of Hantzsch ester 1,4-dihydropyridines with iodine under normal conditions and ultrasound irradiation

A variety of Hantzschester 1,4-dihydropyridines are efficiently oxidized to their corresponding pyridine compounds with iodine under normal conditions and ultra sound irradiation. There actions were carried out in refluxing CH 3CN.