Poly(4-vinylpyridinium butane sulfonic acid) hydrogen sulfate: An efficient, heterogeneous poly(ionic liquid), solid acid catalyst for the one-pot preparation of 1-amidoalkyl-2-naphthols and substituted quinolines under solvent-free conditions

Numerical Simulation of the Dust Production and Transportation Law of an Intermediate Mine Heap

In view of the current serious dust generation and environmental pollution that occur during the unloading process of an intermediate mine heap, in this study, the flow field and dust migration law for an intermediate mine heap were simulated numerically. Based on the mathematical model of the flow field and dust field, a numerical simulation was used to obtain the impact airflow and dust distribution law under different unloading conditions. The effects of different factors on the impact airflow and dust were studied. It could be concluded that the maximum impact wind velocity and dust concentration increased with an increase in the unloading flow. When the heap height is 23 m, the relationship between the maximum impact wind velocity and unloading volume was v = 0.05124(M _p)^0.62584 and the relationship between the dust concentration and mine unloading flow was c = 7.05613(M _p)^0.35002. The smaller the ore particle size, the larger the impact airflow and the greater the dust concentration. The relationship between the maximum impact wind velocity and the particle size was v = 1.54000(d)^-0.23786. The relationship between the dust concentration and ore particle size was c = 30.45323(d)^-0.54273. The greater the maximum impact wind speed, the more the dust generated. The existence of natural wind flow will initially accelerate the speed of dust diffusion and increase the dust concentration, but with the increase in natural wind flow, the diffusion effect will gradually reduce the dust concentration. An increase in the mine heap height will cause the impact wind's speed and influence range to continuously decrease but will only have a small effect on the dust concentration.

Adipic Acid as a Biodegradable Solid Acid Catalyst for One-Pot, Three Component Synthesis of 1-Amidoalkyl-2-naphthols

Background:

1-Amidoalkyl-2-naphthols are an attractive group of organic compounds that can be converted to oxazine heterocycles and aminoalkyl naphthols. The derivatives of 1- amidoalkyl-2-naphthols have significant biological activities and act as drug candidates.

Methods:

1-Amidoalkyl-2-naphthols were synthesized via the three-component condensation reaction of 2-naphthol, acetamide/benzamide and various aldehydes in the presence of 10 mol% of adipic acid as an organocatalyst under solvent-free conditions at 120°C.

Results:

A simple, efficient, and operative method for the synthesis of 1-amidoalkyl-2-naphtholes in the presence of adipic acid as the biodegradable catalyst is introduced. Easy operation, acceptable reaction times, eco-friendly, availability of starting materials, simple separation of products, and high yields of products are the significant results of this method.

Conclusion:

In this study, 1-amidoalkyl-2-naphthols were synthesized using commercially available reactants in excellent yields and relatively shorter times. In this process, microwave or ultrasonic waves were not used to provide energy for the reaction.

Novel polymeric acidic ionic liquids as green catalysts for the preparation of polyoxymethylene dimethyl ethers from the acetalation of methylal with trioxane

A series of micro–mesoporous polymeric acidic ionic liquids (PAILs) have been successfully synthesized and subsequently characterized using Fourier transform-infrared spectroscopy, N₂ adsorption–desorption isotherms, scanning electron microscopy and thermogravimetry. Furthermore, the catalytic performance of the synthesized PAILs was investigated for the acetalation of methylal (DMM₁) with 1,3,5-trioxane (TOX), micro–mesoporous PAILs copolymerized by divinylbenzene with cations and anions exhibited moderate to excellent catalytic activities for the acetalation. In particular, VIMBs–AMPs–DVB, with higher specific surface area (25.51 m² g⁻¹) and total pore volume (0.15 cm³ g⁻¹) displayed an elevated conversion of formaldehyde (82.2%) and selectivity for polyoxymethylene dimethyl ethers (CH₃O(CH₂O)_nCH₃; PODE_n or DMM_n) n = 3–8 (52.6%) at 130 °C, 3.0 MPa for 8 h. Moreover, the influence of various reaction parameters was investigated by employing VIMBs–AMPs–DVB as the catalyst and it demonstrated high thermal stability and easy recovery.

Polyoxymethylene dimethyl ethers were successfully synthesized from acetalation under the catalysis of novel polymeric acidic ionic liquids (PAILs). PAILs copolymerized by divinylbenzene with ILs displayed exceptional catalytic efficiencies.

Green recipes to quinoline: A review

The quinoline core possesses a vast number of biological activities such as anticancer, antimalarial, antimicrobial, antifungal, antitubercular and antileishmanial. The conventional classical synthetic methods require the use of expensive and harsh conditions such as high temperature. Currently the scientific communities are searching new methodology to eliminate the use of chemicals, solvents and catalysts, which are hazardous to human health as well as to environment. This review provides a concise overview of new dimensions of green chemistry approaches in designing quinoline scaffold that would encourage the researchers towards green chemistry as well as future application of these greener, non-toxic, environment friendly methods in designing quinoline scaffold.

Cucurbit[6]uril-OSO3H: a novel acidic nanocatalyst for the one-pot preparation of 14-aryl-14H-dibenzo[a,j]xanthenes and 1,8-dioxo-octahydro-xanthenes

One-pot preparation of 14-aryl-14H-dibenzo[a,j]xanthenes (3a–h) and 1,8-dioxo-octahydro-xanthenes (5a–h).

Synthesis of a 3D-network polymer supported Bronsted acid ionic liquid based on calix[4]resorcinarene via two post-functionalization steps: a highly efficient and recyclable acid catalyst for the preparation of symmetrical bisamides

We report a straightforward route for the synthesis of a novel functional polymer bearing ionic liquid as an efficient and green acidic catalyst for the preparation of bisamides.