3469-21-4

Basic information

• Product Name: 1-benzyl-2,3,4,5-tetramethyl-1H-pyrrole
• Synonyms: 1-Benzyl-2,3,4,5-Tetramethylpyrrole; Pyrrole, 1-benzyl-2,3,4,5-tetramethyl-
• CAS NO: 3469-21-4
• Molecular Formula: C₁₅H₁₉N
• Molecular Weight: 213.3181
• Mol File: 3469-21-4.mol
• Article Data: 3

Chemical Properties

• Boiling Point: 341.3°C at 760 mmHg
• Flash Point: 160.2°C
• Density: 0.95g/cm³
• Vapor Pressure: 0.000161mmHg at 25°C
• Refractive Index: 1.534
• CAS DataBase Reference: 1-benzyl-2,3,4,5-tetramethyl-1H-pyrrole(CAS DataBase Reference)
• NIST Chemistry Reference: 1-benzyl-2,3,4,5-tetramethyl-1H-pyrrole(3469-21-4)
• EPA Substance Registry System: 1-benzyl-2,3,4,5-tetramethyl-1H-pyrrole(3469-21-4)

Safety Data

• Hazardous Substances Data: 3469-21-4(Hazardous Substances Data)

Upstream product

• 28895-02-5 3,4-dimethyl-2,5-hexanedione 
• 100-46-9 benzylamine 
• 28895-03-6 racem. 3,4-dimethyl-hexane-2,5-dione 
• 28895-02-5 meso-3,4-dimethyl-hexane-2,5-dione 

Downstream Products

• 115695-76-6 C₃₈H₄₄N₂ 

Relevant articles and documents

Hexafluoroisopropanol as solvent and promotor in the Paal-Knorr synthesis of N-substituted diaryl pyrroles

An additive-free synthesis of challenging N-substituted aryl pyrroles from the often poorly soluble corresponding 1,4-diketones by means of the Paal-Knorr pyrrole synthesis is reported, which makes use of the unique properties of 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) as a solvent and reaction promotor. Our procedure offers simple execution and purification as well as easy scale-up and can be applied in the Paal-Knorr synthesis of a large number of structurally diverse pyrroles including the synthetically challenging tetra- and penta-substituted pyrroles in moderate to excellent yields. HFIP can also be used as solvent in the Paal-Knorr synthesis of furans and thiophenes; however, the solvent effect is more pronounced in synthesis of pyrroles.

Stereoisomer Effects on the Paal-Knorr Synthesis of Pyrroles

The neurotoxicity of n-hexane has been postulated to result from the reactivity of its γ-diketone metabolite, 2,5-hexanedione (1), with lysil amino groups of proteins to form pyrroles (Paal-Knorr synthesis).We have synthesized a series of 3,4-disubstituted γ-diketones in order to explore the relationship between rate of pyrrole formation and neurotoxicity.The γ-diketones were prepared through oxidative coupling of ketones.Yields were improved to 60-70percent with the use a Soxhlet apparatus containing PbO2 in the extraction thimble.Diketones prepared were 3,4-dimethylhexane-2,5-dione (2), 3,4-diethylhexane-2,5-dione (3), 3,4-diisopropylhexane-2,5-dione (4), and 3,4-diphenylhexane-2,5-dione (5).The reactions yielded mixtures of the d,l (a) and meso (b) diastereomers, which were separated by column chromatography, fractional distillation, or crystallization.Structures of the diastereomeric forms were established by 13C NMR techniques and, in the case of 4b, by single crystal X-ray diffraction.The relative reactivities of the d,l and meso isomers of each γ-diketone were determined with benzylamine in cyclohexane and the rate of pyrrole formation was determined by HPLC.For each pair of diastereomeric diketones the d,l reacted 4-40 times faster than the meso form.The reactivities of the γ-diketones were in the order 2 > 1 > 3 > 5 > 4 with pseudo-first-order rate constants ranging from 4*10-4 to 3*10-8 s-1 at 30 deg C.