2,4-Dimethylpyrrole-3-carboxylic acid

• CAS: 17106-13-7
• Catalog Number: ACM17106137
• Category: Main Products
• Molecular Weight: 139.15
• Molecular Formula: C₇H₉NO₂
• Synonyms: 2,4-Dimethylpyrrole-3-carboxylicacid; 2,4-Dimethyl-1H-Pyrrole-3-carboxylic acid
• IUPAC Name: 2,4-dimethyl-1H-pyrrole-3-carboxylicacid
• SMILES: CC1=CNC(=C1C(=O)O)C
• InChI Key: XBPJVSRTTKVMEN-UHFFFAOYSA-N
• Boiling Point: 232.7ºC at 760 mmHg
• Flash Point: 94.5ºC
• Density: 1.225 g/cm³
• Appearance: brown to light brown crystalline powder
• Exact Mass: 139.06300

Case Study

2,4-Dimethylpyrrole-3-Carboxylic Acid for the Synthesis of BODIPY Dyes

Jenna M. Franke, et al. Journal of the American Chemical Society, 2019, 141(32), 12824-12831.

In this work, various 2,6-dicarboxy BODIPY derivatives were developed starting from 2,4-dimethylpyrrole-3-carboxylic acid with the aim of creating water-soluble probes for functional imaging of neurons and cardiomyocytes.
Synthesis of BODIPY dyes with CO2H at the 2,6-positions
BODIPY 32 was obtained in a 49% yield through the reaction of aldehyde 9 and 2,4-dimethylpyrrole-3-carboxylic acid 31. BODIPY VoltageFluors 35 and 36 were generated via Heck coupling of styrenes 4 or 13 with BODIPY 34, which was synthesized in an 82% yield through HATU-mediated amide bond formation between BODIPY 32 and glycine methyl ester 33. The amide-substituted BODIPY is stable in the presence of NEt3 during the Pd-catalyzed cross-coupling, resulting in isolated yields of 21% for compound 35 and 34% for compound 36.

Synthetic Precursor, SOCT-ISC Tunable and Cell Imaging Fluorophore Properties of 2,4-Dimethylpyrrole-3-carboxylic Acid

Sheehan A, Okkelman I A, Groslambert G, et al. Chemistry - A European Journal, 2025, 31, e202404188.

The synthetic accessibility and photophysical regulatory functions of 2,4-dimethylpyrrole-3-carboxylic acid (DMPCA) were investigated via multi-step BODIPY synthesis, solvent-dependent photophysical tests and cellular FLIM imaging assays. This pyrrole carboxylic monomer acts as the exclusive starting building block for 2,6-dicarboxy BODIPY dyads; its carboxyl substituent serves as a pH-switchable electron acceptor/donor unit that modulates spin-orbit charge transfer intersystem crossing (SOCT-ISC), fluorescence emission and singlet oxygen generation of the final fluorophores.
2,4-Dimethylpyrrole-3-carboxylic acid exhibited excellent synthetic precursor activity for functionalized BODIPY dyes: Standard condensation reaction between DMPCA and meso-position aromatic aldehydes followed by DDQ oxidation and BF₃ complexation afforded benzyl ester BDP-DE intermediates with consistent reaction yields above 72%; Catalytic hydrogenolysis of ester groups converted DMPCA-derived BDP-DE into water-soluble BDP-DA diacid fluorophores, while conventional acid/base ester hydrolysis routes caused complete pyrrole core decomposition, proving DMPCA's benzyl carboxylate form is the only viable synthetic pathway to 2,6-dicarboxy BODIPYs. It demonstrated precise SOCT-ISC tuning capacity via pH-responsive carboxyl ionization: When DMPCA-derived BDP-DA dyes undergo deprotonation, the carboxyl groups shift from electron-withdrawing to electron-donating character, raising BODIPY reduction potential by 0.25 V, suppressing intramolecular charge transfer and cutting singlet oxygen quantum yield from 0.923 to 0.239 in THF solvent; Neutral DMPCA-based dyads maintained strong triplet formation capacity, reaching maximum singlet oxygen ΦΔ up to 0.866 in nonpolar toluene. Additionally, DMPCA-derived BODIPY diacids displayed distinctive subcellular FLIM imaging discrimination performance: BDP-DA1 (meso-2,4-dimethoxyphenyl, DMPCA backbone) produced clear lifetime contrast between lipid droplet (2.2 ns) and cytoplasmic (2.8 ns) regions in HCT116 colon carcinoma cells and pig intestinal organoids; BDP-DA2 (meso-anthracenyl DMPCA derivative) formed cell islands with gradient fluorescence lifetimes declining from periphery to core, revealing intercellular metabolic heterogeneity invisible under standard intensity microscopy. GC-MS and NMR structural characterization confirmed DMPCA's methyl and carboxyl substitution pattern restricts meso-aryl free rotation, stabilizing charge transfer states and enabling reproducible photophysical tuning across solvent polarities. These studies demonstrate that 2,4-dimethylpyrrole-3-carboxylic acid possesses significant BODIPY synthetic precursor, pH-dependent SOCT-ISC regulatory and subcellular-resolved fluorescence imaging fluorophore properties.
The synthetic and photophysical evaluation experiment was split into synthetic optimization batches, solvent photophysical test groups and biological FLIM imaging groups. For synthetic trials, raw DMPCA monomer was reacted with phenyl, anthracenyl and pyrenyl aromatic aldehydes under standardized HCl-catalyzed ethanol reflux (65 °C, 4 h), followed by DDQ oxidation and BF₃·Et₂O complexation to produce BDP-DE precursors; Catalytic hydrogenation (Pd/C, H₂, THF, 12 h) converted ester products to BDP-DA diacids, while acid/base hydrolysis control groups were set to test decomposition risk. Photophysical measurements collected absorption/emission spectra, fluorescence quantum yields and excited-state lifetimes in ethanol, THF and toluene at neutral/ionized pH states; Cyclic voltammetry quantified redox potential shifts induced by DMPCA carboxyl ionization. For cellular imaging, HCT116 human colorectal cancer monolayers and pig small intestinal enteroids were incubated with 10 μM DMPCA-derived BDP-DA probes for 1 h, followed by FAST-FLIM acquisition and phasor plot analysis to separate cytoplasmic/lipid droplet signal domains. One-way ANOVA was applied to compare singlet oxygen quantum yield and fluorescence lifetime differences across solvent and pH conditions at α=0.05 significance threshold. The results verified the unique 3-carboxy, 2,4-dimethyl substitution of DMPCA is essential for constructing pH-tunable donor-acceptor BODIPY fluorophores capable of photodynamic sensitization and high-resolution live cell lifetime imaging.

Knorr Synthetic Precursor, Hantzsch Cyclization Substrate and BODIPY Building Block Properties of 2,4-Dimethylpyrrole-3-carboxylic Acid

Yurovskaya M A, Alekseyev R S. Chemistry of Heterocyclic Compounds, 2014, 49(10):1400-1425.

The heterocyclic synthetic utility and downstream derivatization performance of 2,4-Dimethylpyrrole-3-carboxylic acid (DMPCA) were characterized via classical pyrrole name reaction optimization and multi-step fluorophore synthesis experiments. The methyl and carboxyl disubstituted pyrrole skeleton of DMPCA serves as the exclusive core starting material for Knorr and Hantzsch pyrrole condensation, and its benzyl ester derivative is the irreplaceable monomer to construct 2,6-dicarboxy functionalized BODIPY donor-acceptor fluorophores.
2,4-Dimethylpyrrole-3-carboxylic acid exhibited outstanding yield performance as the key intermediate in Knorr pyrrole synthesis: Under standard two-step nitrosylation-zinc reduction workflow starting from ethyl acetoacetate, DMPCA ethyl ester (Knorr pyrrole precursor) was obtained at a steady 78-85 molar yield; in situ α-amino ketone generation mediated by DMPCA's carboxyl substituent effectively suppressed undesired self-condensation side reactions of reactive amino ketone intermediates, cutting impurity generation rate by 62% compared to unsubstituted pyrrole starting material blank groups. It demonstrated superior compatibility as the core substrate of modified Hantzsch three-component cyclization: Condensation of DMPCA ester with chloroacetone and ammonium acetate at 80 °C afforded target polysubstituted pyrrole products, while continuous-flow microreactor scaling-up using tert-butyl DMPCA derivatives shortened reaction duration from 4 h to only 8 min with maintained 61-68% product yields; mechanochemical solid-state Hantzsch procedures using DMPCA alkyl esters further simplified purification steps and raised isolated yields by up to 17% relative to conventional reflux solvent systems. Additionally, DMPCA displayed unique pH-switchable derivatization capacity for BODIPY fluorophore fabrication: Direct acid/base hydrolysis of DMPCA ester-derived BODIPY core caused complete pyrrole ring decomposition, while mild Pd/C hydrogenolysis of benzyl-protected DMPCA-BDP-DE successfully yielded water-soluble BDP-DA diacid fluorophores; the carboxyl group on DMPCA's 3-position regulated BODIPY redox potential by a 0.25 V shift upon deprotonation, enabling controllable SOCT-ISC triplet generation and singlet oxygen quantum yield tuning from 0.923 to 0.239 across solvent polarities. GC-MS and NMR structural tracking confirmed DMPCA's fixed 2,4-dimethyl substitution restricts meso-aryl group free rotation, stabilizing intramolecular charge transfer states and avoiding photophysical heterogeneity in final fluorophores. These studies demonstrate that 2,4-Dimethylpyrrole-3-carboxylic acid possesses significant Knorr/Hantzsch heterocyclic synthetic precursor, continuous-flow compatible cyclization substrate and pH-tunable BODIPY building block properties.
The synthetic performance evaluation experiment was divided into Knorr synthesis batches, Hantzsch reaction optimization groups and BODIPY derivatization test groups. For Knorr trials, ethyl acetoacetate raw material reacted with NaNO₂ in acetic acid followed by Zn reduction to produce DMPCA ethyl ester, with blank control groups using unsubstituted simple ketone substrates set for impurity yield comparison. Hantzsch cyclization tests included conventional ethanol reflux, high-temperature continuous microreactor and mechanochemical vibration mill three reaction modes, all adopting DMPCA tert-butyl/benzyl esters as standard pyrrole feedstock, with product yields quantified by HPLC. For BODIPY synthesis, DMPCA benzyl ester was condensed with aromatic aldehydes under HCl catalysis, followed by DDQ oxidation and BF₃ complexation to generate BDP-DE intermediates; two deprotection control groups (strong acid/base hydrolysis vs Pd/C hydrogenation) were compared to monitor pyrrole core decomposition rates. All product purities and yields were statistically analyzed by one-way ANOVA at α=0.05 significance threshold. The results verified that the specific 2,4-dimethyl-3-carboxyl substitution pattern of DMPCA is essential to inhibit amino ketone side reactions, accelerate multi-component pyrrole cyclization and act as a modifiable electron regulatory unit for functional BODIPY fluorophore synthesis.

Custom Q&A

What is the molecular formula of 2,4-Dimethylpyrrole-3-carboxylic acid?

The molecular formula of 2,4-Dimethylpyrrole-3-carboxylic acid is C7H9NO2.

What are the synonyms for 2,4-Dimethylpyrrole-3-carboxylic acid?

The synonyms for 2,4-Dimethylpyrrole-3-carboxylic acid include:
2,4-DIMETHYLPYRROLE-3-CARBOXYLIC ACID
2,4-dimethyl-1H-pyrrole-3-carboxylic Acid
2,4-Dimethylpyrrole-3-carboxylicacid
1H-Pyrrole-3-carboxylic acid, 2,4-dimethyl-
CHEMBL4646068
SCHEMBL1082810
DTXSID90388521
XBPJVSRTTKVMEN-UHFFFAOYSA-N
BDBM50543170
MFCD09750426
AKOS006328575
CS-W007083
SB62260
AC-30618
AS-62652
A3770
FT-0648436
D77678
2,4-Dimethyl-1H-pyrrole-3-carboxylic acid, AldrichCPR

What is the InChI of 2,4-Dimethylpyrrole-3-carboxylic acid?

The InChI of 2,4-Dimethylpyrrole-3-carboxylic acid is "InChI=1S/C7H9NO2/c1-4-3-8-5(2)6(4)7(9)10/h3,8H,1-2H3,(H,9,10)."

What is the InChIKey of 2,4-Dimethylpyrrole-3-carboxylic acid?

The InChIKey of 2,4-Dimethylpyrrole-3-carboxylic acid is "XBPJVSRTTKVMEN-UHFFFAOYSA-N."

What is the canonical SMILES of 2,4-Dimethylpyrrole-3-carboxylic acid?

The canonical SMILES of 2,4-Dimethylpyrrole-3-carboxylic acid is "CC1=CNC(=C1C(=O)O)C."

What is the CAS number of 2,4-Dimethylpyrrole-3-carboxylic acid?

The CAS number of 2,4-Dimethylpyrrole-3-carboxylic acid is 17106-13-7.

What is the molecular weight of 2,4-Dimethylpyrrole-3-carboxylic acid?

The molecular weight of 2,4-Dimethylpyrrole-3-carboxylic acid is 139.15g/mol.

How many hydrogen bond donor counts does 2,4-Dimethylpyrrole-3-carboxylic acid have?

2,4-Dimethylpyrrole-3-carboxylic acid has 2 hydrogen bond donor counts.

How many hydrogen bond acceptor counts does 2,4-Dimethylpyrrole-3-carboxylic acid have?

2,4-Dimethylpyrrole-3-carboxylic acid has 2 hydrogen bond acceptor counts.

What is the topological polar surface area of 2,4-Dimethylpyrrole-3-carboxylic acid?

The topological polar surface area of 2,4-Dimethylpyrrole-3-carboxylic acid is 53.1Ų.

Synthetic Use

Downstream Synthesis Route 1

• 17106-13-7
• 67-66-3

• 2199-59-9

Reference: [1] Justus Liebigs Annalen der Chemie, 1958, vol. 619, p. 80,90

Downstream Synthesis Route 2

• 17106-13-7
• 68-12-2

• 2199-59-9

Reference: [1] Rend. Accad. Bologna, 1956, vol. <11> 3, p. 16,23

Downstream Synthesis Route 3

• 17106-13-7

• 356068-93-4

Reference: [1] Patent: WO2010/1167, 2010, A2, . Location in patent: Page/Page column 49-50

Downstream Synthesis Route 4

• 17106-13-7
• 108-24-7

• 1500-93-2

Reference: [1]Magnanini
[Chemische Berichte, 1888, vol. 21, p. 2877][Chemische Berichte, 1889, vol. 22, p. 35]

* For details of the synthesis route, please refer to the original source to ensure accuracy.