32570-10-8

Upstream product

• 110-13-4 2,5-hexanedione 
• 108-44-1 1-amino-3-methylbenzene 
• 74-86-2 acetylene 
• 625-86-5 2,5-dimethylfuran 
• 99-08-1 1-methyl-3-nitrobenzene 
• 1333-74-0 hydrogen 

Downstream Products

• 83-18-1 2,5-dimethyl-1-phenyl-1H-pyrrole-3-carbaldehyde 
• 423749-16-0 2,5-dimethyl-1-(3-methylphenyl)-1H-pyrrole-3-carbaldehyde 

Relevant academic research and scientific papers

Silica tungstic acid and sulphated silica tungstic acid as highly efficient solid acid catalysts for the synthesis of pyrrole derivatives

In the present study silica supported tungstic acid (STA) and sulphated silica tungstic acid (SSTA) were applied as efficient and cost-effective solid acid catalysts in the synthesis of N-substituted pyrrole derivatives via the Paal–Knorr reaction of 2,5-hexadione with aromatic and aliphatic amines at room temperature. The reaction completed in short time under mild conditions with high yield. The catalysts could be easily recovered upon reaction completion. Structures of all products were confirmed by elemental analysis, FT-IR, 1H and 13C NMR spectra.

A New FXR Ligand Chemotype with Agonist/Antagonist Switch

Therapeutic modulation of the bile acid-sensing transcription factor farnesoid X receptor (FXR) is an appealing strategy to counteract hepatic and metabolic diseases. Despite the availability of several highly potent FXR agonists structural diversity of FXR modulators is limited, and new ligand scaffolds are needed. Here we report structure-activity relationship elucidation of a new FXR modulator chemotype whose activity can be tuned between agonism and antagonism by two minor structural modifications. Starting from a weak FXR/PPAR agonist, we have developed selective FXR activators and antagonists with nanomolar to low-micromolar potencies and binding affinities. The new FXR ligand chemotype modulates the FXR activity in the native cellular setting, is endowed with favorable metabolic stability, and lacks cytotoxicity. It valuably expands the collection of FXR modulators as a new scaffold for FXR-targeted drug discovery.

Crystalline salicylic acid as an efficient catalyst for ultrafast Paal–Knorr pyrrole synthesis under microwave induction

Abstract: In this study, the viability of a wide range of crystalline aromatic and aliphatic carboxylic acids as organocatalysts has been investigated for solvent-free Paal–Knorr pyrrole synthesis under microwave activation. Among these potential catalysts, crystalline salicylic acid proved to be a remarkable catalyst because its efficiency remained high even under low microwave power irradiation or a shorter reaction time for the model reaction. The outstanding catalytic activity of salicylic acid allowed the Paal–Knorr cyclocondensation with a turnover frequency up to 1472?h?1 which is unique in the context of a metal-free homogeneous catalysis. The attractive feature of this organocatalyst is its assistance in ultrafast pyrrole synthesis with no risk of metal contamination. Graphic abstract: [Figure not available: see fulltext.] Synopsis: A green and expeditious protocol for the synthesis of 2,5-dimethylpyrroles via combination of salicylic acid as catalyst (in its solid state) and microwaves has been introduced.

Preparation method of biomass-based 2, 5-dimethyl-N-substituted pyrrole derivative

The invention discloses a preparation method of a biomass-based 2, 5-dimethyl-N-substituted pyrrole derivative. The method comprises the following steps: adding 2, 5-dimethylfuran, an amine compound, a catalyst, distilled water and 2mL of solvent into a reaction kettle, and heating the reaction kettle in an oil bath pan; and obtaining the 2, 5-dimethyl-N-substituted pyrrole derivative after the temperature is 110-170 DEG C, the use amount of distilled water is 0-250 [mu] L, the use amount of the catalyst is 5-10 wt%, and the reaction time is 1-3 h. The method overcomes the defects of high cost and difficulty in separation and recovery of the existing catalyst or catalyst system.

Naturally occurring organic acids for organocatalytic synthesis of pyrroles via Paal–Knorr reaction

Abstract: In this study, common naturally occurring organic acids, namely oxalic, malonic, succinic, tartaric and citric acid (as safe, inexpensive, and biodegradable organocatalysts), have been employed for Paal–Knorr pyrrole synthesis. The organocatalyzed reaction proved to be effective in ethanol at 60?°C. However, the reaction rate is mainly dominated by the nature and position of functional groups on the aromatic ring of substrate. This metal-free procedure tolerates a series of functional groups and should be considered as an asset to the pharmaceutical industry since no metal contamination could take place during the synthesis of pyrrole scaffolds. Graphic abstract: [Figure not available: see fulltext.].

Superbase-promoted multi-molecular acetylene/arylamine self-organization to 1-arylpyrroles

A new superbase-promoted reaction of acetylene involves self-organization of its three molecules with one molecule of arylamine in KOH/DMSO system to afford 1-aryl-2,5- dimethylpyrroles in up to 63% yields. The key step of this reaction cascade is assumed to be the nucleophilic addition of acetylene to the C = N bond of the intermediate aldimine (aza-Favorsky reaction).

Grinding solvent-free paal-knorr pyrrole synthesis on smectites as recyclable and green catalysts

An environmentally benign method for the synthesis of N-substituted pyrroles from one-pot solvent-free condensation reaction of 2,5-hexanedione with various primary amines (Paal-Knorr pyrrole synthesis) on smectite clays as green and reusable heterogeneous Lewis acid catalysts is presented. The use of nontoxic, inexpensive, easily available and reusable catalysts under solvent-free conditions make this protocol practical, environmentally friendly and economically attractive.

Microwave-induced calcium(II) chloride-catalyzed Paal–Knorr pyrrole synthesis: a safe, expeditious, and sustainable protocol

Abstract: Among various alkali (Na, K) and alkaline-earth (Ca, Mg, Sr, Ba) chlorides, calcium(II) chloride was found to be a cost-effective Lewis acid catalyst for solvent-free synthesis of pyrroles from primary aromatic and aliphatic amines under open-vessel focused microwave irradiation. The salient features of this environmentally benign method are high to quantitative conversion, short reaction time, safe and clean reaction profile, possibility of scale-up to multigram quantities, and use of a low-cost, widely available, nontoxic catalyst.

Direct Synthesis of Pyrroles via Heterogeneous Catalytic Condensation of Anilines with Bioderived Furans

Given the wide applications of pyrroles in agriculture, pharmaceuticals, and supramolecular and materials chemistry, a mild and eco-friendly route to produce functionalized pyrroles from bioderived feedstocks is highly desirable. Described herein is a mild and convenient synthesis of pyrroles via direct condensation of an equimolar amount of structurally diverse anilines with biobased furans catalyzed by a simple and efficient solid acid H form zeolite Y catalyst. The protocol tolerates a large variety of functional groups and offers a general and versatile method for scale-up synthesis of a variety of N-substituted pyrrole compounds. Most importantly, the bioactive pyrrole-derived drug pyrvinium, which has lately been confirmed as highly effective in curing colon cancer, can be obtained by this method.

One-pot synthesis of: N -substituted pyrroles from nitro compounds and 2,5-hexadione over a heterogeneous cobalt catalyst

In this study, the one-pot heterocyclization of nitro compounds with 2,5-hexadione was studied for the synthesis of N-substituted pyrroles via a Paal-Knorr condensation process. The heterogeneous cobalt-nitrogen catalyst (Co-Nx/C-800-AT) was found to be active for this reaction with formic acid. Formic acid served as a hydrogen donor for the transfer hydrogenation, and also acted as an acid catalyst. More importantly, this method was tolerant of other functional groups, and hence various N-substituted pyrroles were produced with good to excellent yields. The Co-Nx/C-800-AT catalyst was highly stable, and could be reused several times without loss of its catalytic activity.