Category: 26187-28-0

Badger, G. M. published the artcilePorphyrins. V. The cyclization of linear tetrapyrroles, Recommanded Product: 2,4-Dimethyl-1H-pyrrole-3-carbonitrile, the publication is Australian Journal of Chemistry (1964), 17(9), 1013-21, database is CAplus.

cf. CA 61, 13265c. Tetrapyrrenes (I) were prepared by condensation of 3-acetyl-2,4-dimethylpyrrole (II) or of 3-cyano-2,4-dimethylpyrrole (III) with 5,5′-bis(methoxymethyl)-3,3′,4,4′-tetramethyldipyrromethane-HBr (IV). A mixture of 100 g. 5-ethoxycarbonyl-2,3,4trimethylpyrrole, 100 ml. 98% HCO₂H, and 100 ml. 48% HBr was heated 8 hrs. on a steam bath and left overnight to yield 83 g. 3,3′,4,4′,5,5′-hexamethyldipyrromethene-HBr (V), m. 308-10°. Br (16 g.) in 20 ml. HOAc was added during 30 min. to a stirred and heated mixture (70-5°) of 12 g. V in 100 ml. HOAc, and the mixture stirred 30 min. at 75° and cooled to yield 15 g. 5,5′-bis(bromomethyl)-3,3′,4,4′-tetramethyldipyrromethene-HBr (VI), m. >300°. VI (5 g.) in 50 ml. MeOH was refluxed 30 min., the solution cooled, 100 ml. ether added, the mixture left overnight at 0° the separated product dissolved in boiling C₆H₆, and the solution diluted with boiling petr. ether and cooled to yield 2.7 g. IV, m. 174-6°. The oxime of 2-ethoxycarbonyl-4-formyl-3,5-dimethylpyrrole was converted into the nitrile, mild alk. hydrolysis of which yielded 5-carboxy-3-cyano-2,4-dimethylpyrrole, which on decarboxylation by refluxing 1 hr. with ethanolamine yielded III, m. 107°. A solution of 1 g. IV and 0.75 g. II in 20 ml. C₆H₆ was refluxed 1 hr. and cooled to yield 0.92 g. I.HBr (R = Ac) (VI), m. 235° [decomposition, darkening at 225° (CHCl₃-petr. ether]. Similarly, 1.5 g. IV and 1 g. III in 30 ml. C₆H₆ was refluxed 1 hr., cooled, diluted with 15 ml. ether, and refrigerated to yield I.HBr (R = CN) (VII), m. 235-40° (decomposition) (CHCl₃-petr. ether). VI (0.I g.) was dissolved in 100 ml. MeOH, the mixture refluxed 1 hr., 0.2 g. Cu(OAc)₂ added, the mixt refluxed 48 hrs., MeOH evaporated, the residue extracted 3 hrs. (Soxhlet) with CHCl₃, the CHCl₃ extract concentrated, the residue dissolved in concentrated H₂SO₅, the solution left 3 hrs. at room temperature, poured on ice, the mixture extracted with CHCl₃, and the extract washed with NH₄OH, H₂O, dried, and chromatographed over grade IV Al₂O₃, using CHCl₃-petr. ether for elution. The red band exhibiting red fluorescence was eluted first, and the solution evaporated to give 1,2 – diacetyl – 3,4,5,6,7,8- hexamethylporphine (VIII), which was dissolved in CHCl₃, λ 420, 518, 556, 588 and 642.7 m. A portion of this solution was evaporated, the residue dissolved in 4:1 C₅H₅N-H₂O, NH₂OH.HCl added, and the mixture heated 30 min. on a steam-bath. The resulting solution showed λ 505, 537.5, 572.5 and 625.8 mμ. A 2nd portion of the CHCl₃ solution was evaporated, the residue dissolved in dioxane, aqueous NaBH₄ solution added, the mixture left overnight, worked up, and the product taken up in CHCl₃, washed with NH₄OH, H₂O, and dried. The resulting solution had 501.7, 534.2,568.3 and 623.3 mμ. Alternatively, 2 g. 1′,1,8′-dideoxy-1′,2,3,4,5,6,7,8′-octamethylbilene-b-HBr was dissolved in 1 l. MeOH by refluxing 1 hr., 4 g. Cu(OAc)₂ added, the mixture refluxed 1 week and filtered, the residue extracted 1 hr. (Soxhlet) with MeOH, the extract filtered (Celite), and the residue and Celite extracted again (Soxhlet) with CHCl₃ 2 hrs. (extract A) and then with fresh CHCl₃ for 18 hrs. (extract B). Cohen. of extract B yielded 0.05 g. VIII Cu complex, m. 316-18° (decomposition). Extract A was evaporated, the residue dissolved in 20 ml. concentrated H₂SO₄, the mixture left 1 hr., poured on 400 g. crushed ice and the separated solid extracted (Soxhlet) with CHCl₃ Evaporation of the CHCl₃ extract yielded 0.08 g. VIII, m. >360° as steel-blue-needles. Cyclization of VII under similar conditions gave 2 porphyrins, presumably 1-cyano-3,4,5,6,7,8hexamethylporphine (λ 412,516.2, 522,571,621 and 636 mμ) and 1,2-dicyano-3,4,5,O,7,8-hexamethylporphine (λ 420, 519, 555, 590.2 and 643.5 mμ) in poor yield.

Australian Journal of Chemistry published new progress about 26187-28-0. 26187-28-0 belongs to nitriles-buliding-blocks, auxiliary class Pyrrole,Nitrile, name is 2,4-Dimethyl-1H-pyrrole-3-carbonitrile, and the molecular formula is C7H8N2, Recommanded Product: 2,4-Dimethyl-1H-pyrrole-3-carbonitrile.

Referemce:
https://en.wikipedia.org/wiki/Nitrile,
Nitriles – Chemistry LibreTexts

Wen, Hui published the artcileA high-resolution method to assess cell multinucleation with cytoplasm-localized fluorescent probes, Quality Control of 26187-28-0, the publication is Analyst (Cambridge, United Kingdom) (2016), 141(13), 4010-4013, database is CAplus and MEDLINE.

Cell multinucleation is closely related to chromosomal instability. We report a simple, convenient method to assess cell multinucleation with cytoplasm-localized fluorescent probes (CLFP) which is superior to conventional nuclear staining methods. The CLFP method provides high-resolution images that enable the accurate calculation of the number of nuclear fragments.

Analyst (Cambridge, United Kingdom) published new progress about 26187-28-0. 26187-28-0 belongs to nitriles-buliding-blocks, auxiliary class Pyrrole,Nitrile, name is 2,4-Dimethyl-1H-pyrrole-3-carbonitrile, and the molecular formula is C27H39ClN2, Quality Control of 26187-28-0.

Referemce:
https://en.wikipedia.org/wiki/Nitrile,
Nitriles – Chemistry LibreTexts

Krumova, Katerina published the artcileBodipy Dyes with Tunable Redox Potentials and Functional Groups for Further Tethering: Preparation, Electrochemical, and Spectroscopic Characterization, Name: 2,4-Dimethyl-1H-pyrrole-3-carbonitrile, the publication is Journal of the American Chemical Society (2010), 132(49), 17560-17569, database is CAplus and MEDLINE.

The preparation, spectroscopic, and electrochem. characterization of a family of 16 new bodipy dyes with tunable redox potentials and versatile functional groups is reported. Electron-withdrawing or -donating groups (Et, H, Cl, or CN) at positions C2 and C6 enabled tuning the redox potentials within a ca. 0.7 eV window without significantly affecting either the HOMO-LUMO gap or the absorption and emission spectra. Hydroxymethyl or formyl groups at the meso (C8) position in turn provided a handle for covalent tethering to receptors and biomols. of interest, which dispenses with the more commonly used meso-aryl moiety as a means to tag mols. The dyes can thus be coupled to both electrophiles and nucleophiles. Importantly, it is shown that meso-formyl bodipy dyes are nonemissive and have significantly lower molar extinction coefficients compared to their meso-hydroxymethyl and meso-acetoxymethyl counterparts (which in turn are bright, with emission quantum yields in the range of 0.7-1). The nonemissive meso-formyl bodipy dyes thus provide unique opportunities as fluorogenic probes of nucleophilic attack and as fluorescent labeling agents where uncoupled fluorophores will not contribute to the fluorescence background. Overall, the new bodipy dyes reported here are promising candidates for the preparation of fluorescent sensors relying on photoinduced electron transfer and may find use in a number of fluorescent-labeling protocols.

Journal of the American Chemical Society published new progress about 26187-28-0. 26187-28-0 belongs to nitriles-buliding-blocks, auxiliary class Pyrrole,Nitrile, name is 2,4-Dimethyl-1H-pyrrole-3-carbonitrile, and the molecular formula is C7H8N2, Name: 2,4-Dimethyl-1H-pyrrole-3-carbonitrile.

Referemce:
https://en.wikipedia.org/wiki/Nitrile,
Nitriles – Chemistry LibreTexts

Sathyamoorthi, Govindarao published the artcileLaser active cyanopyrromethene-BF₂ complexes, Product Details of C7H8N2, the publication is Heteroatom Chemistry (1994), 5(4), 403-7, database is CAplus.

Treatment with a mixture of formic and hydrobromic acids converted Et 3,4-diethyl-5-methylpyrrole-2-carboxylate to 3,3,’,4,4′-tetraethyl-5,5′-dimethylpyrromethene hydrobromide presumably via the condensation of α-unsubstituted and α-formylpyrrole intermediates formed in situ. The corresponding 6-cyanohexaalkylpyrromethane was obtained by the addition of hydrogen cyanide to the pyrromethene and was oxidized with bromine to an unstable pyrromethene, an intermediate converted to 1,2,6,7-tetraethyl-3,5-dimethyl-8-cyanopyrromethene-BF₂ complex(PM-TEDC), λ_las (plastic) 613-639 nm, in a reaction with boron trifluoride etherate. Et 3,4,5-trimethylpyrrole-2-carboxylate was similarly converted to 1,2,3,5,6,7-hexamethyl-8-cyanopyrromethene-BF₂ complex, (PM-HMC), λ_las (plastic) 615-639 nm. Immediately after formation by a condensation between propionyl chloride and 2,4-dimethyl-3-cyanopyrrole, unstable 3,3′,5,5′-tetramethyl-6-ethyl-4,4′-dicyanopyrromethene hydrochloride was treated with boron trifluoride etherate to give 1,3,5,7-tetramethyl-2,6-dicyano-8-ethylpyrromethene-BF₂ complex, λ_las (ethanol) 540-565 nm.

Heteroatom Chemistry published new progress about 26187-28-0. 26187-28-0 belongs to nitriles-buliding-blocks, auxiliary class Pyrrole,Nitrile, name is 2,4-Dimethyl-1H-pyrrole-3-carbonitrile, and the molecular formula is C7H8N2, Product Details of C7H8N2.

Referemce:
https://en.wikipedia.org/wiki/Nitrile,
Nitriles – Chemistry LibreTexts