Tag: M.W=250-300

Akaji, K. published the artcileSynthesis of cyclic RGD derivatives via solid phase macrocyclization using the Heck reaction, Recommanded Product: 1-((9H-Fluoren-9-yl)methyl)piperidine, the publication is Tetrahedron (2001), 57(12), 2293-2303, database is CAplus.

A novel intramol. macrocyclization reaction on a solid support using the Heck reaction has been achieved. For head to tail cyclization on a solid support, the linear precursor was anchored to a chlorotrityl chloride resin via an ester linkage using the β-carboxyl group of Asp. The Heck coupling of acrylic acid amide to 3-iodobenzylamine on the solid support proceeds smoothly to yield a cyclic tetrapeptide derivative, which contains a new 3-substituted cinnamic acid template and Arg-Gly-Asp sequence. The macrocyclization reaction takes place considerably more rapidly on a solid support than in solution The solid phase procedure was successfully used for the construction of cyclic RGD libraries having diverse side chain structures, combined with a variety of ring sizes.

Tetrahedron published new progress about 35661-58-6. 35661-58-6 belongs to piperidines, auxiliary class Piperidine,Benzene, name is 1-((9H-Fluoren-9-yl)methyl)piperidine, and the molecular formula is C19H21N, Recommanded Product: 1-((9H-Fluoren-9-yl)methyl)piperidine.

Referemce:
https://en.wikipedia.org/wiki/Piperidine,
Piperidine | C5H11N – PubChem

Clapham, Bruce published the artcileUse of a scintillant-containing macroporous resin in both solid phase synthesis and subsequent on-bead scintillation-based analysis, Related Products of piperidines, the publication is Tetrahedron Letters (2000), 41(13), 2257-2260, database is CAplus.

A chem.-functionalized scintillant-containing divinylbenzene-2,5-diphenyl-4-vinyloxazole-4-ethylstyrene-4-vinylbenzyl chloride copolymer macroporous resin was used successfully in a two stage solid phase organic synthesis. The second step in this synthesis involved the covalent attachment of a tritiated acetate group to the resin. The resultant radiolabeled scintillant-containing resin beads scintillate spontaneously and with high efficiency due to the close proximity of the tritium atoms to the scintillant mols. within the beads.

Tetrahedron Letters published new progress about 35661-58-6. 35661-58-6 belongs to piperidines, auxiliary class Piperidine,Benzene, name is 1-((9H-Fluoren-9-yl)methyl)piperidine, and the molecular formula is C19H21N, Related Products of piperidines.

Referemce:
https://en.wikipedia.org/wiki/Piperidine,
Piperidine | C5H11N – PubChem

Cueto-Diaz, Eduardo J. published the artcileCO₂ adsorption capacities of amine-functionalized microporous silica nanoparticles, Formula: C19H21N, the publication is Reactive & Functional Polymers (2022), 105100, database is CAplus.

Efforts on CO₂ capture have intensified as climate change compromises ecosystems and biodiversity. Therefore, it is crucial to develop different methods for CO₂ sequestration to improve solid sorbent capabilities (NPs). To this end, the surface of 200-nm silica nanoparticles (SiO₂NPs) was covalently anchored with aminated ligands, 3-aminopropyltriethoxysilane (APTES), poly(amidoamine) dendrimers (PAMAM) and a short peptide comprising two lysine units, aiming for CO₂ adsorption over a wide range of pressures. Our goal was to explore the influence of functional chem. groups (attached to the SiO₂NPs) on CO₂ sequestration. The observed results showed that at low and high CO₂ gas pressure conditions, typical APTES functionalized SiO₂Np surpassed the CO₂ adsorption capacities of dendritic and peptide-based nanoparticles bearing amine-polymer functionalities, a remarkable effect that was investigated in this work. In addition, a convenient and facile method to decorate and quantify SiO₂ nanoparticles with PAMAM and a short peptide is reported.

Reactive & Functional Polymers published new progress about 35661-58-6. 35661-58-6 belongs to piperidines, auxiliary class Piperidine,Benzene, name is 1-((9H-Fluoren-9-yl)methyl)piperidine, and the molecular formula is C19H21N, Formula: C19H21N.

Referemce:
https://en.wikipedia.org/wiki/Piperidine,
Piperidine | C5H11N – PubChem

Ma, Yunxi published the artcileThe 9-fluorenylmethyloxycarbonyl group as a 5′-OH protection in oligonucleotide synthesis, Application of 1-((9H-Fluoren-9-yl)methyl)piperidine, the publication is Biopolymers (1989), 28(5), 965-73, database is CAplus and MEDLINE.

Oligo-DNAs are synthesized on a solid support using the 9-fluorenylmethyloxycarbonyl group as a 5′-OH base labile protection. The synthesis of the pure protected nucleotides, a relevant phosphoramidite-type strategy of coupling, and the optimization of the deprotection steps are described.

Biopolymers published new progress about 35661-58-6. 35661-58-6 belongs to piperidines, auxiliary class Piperidine,Benzene, name is 1-((9H-Fluoren-9-yl)methyl)piperidine, and the molecular formula is C19H21N, Application of 1-((9H-Fluoren-9-yl)methyl)piperidine.

Referemce:
https://en.wikipedia.org/wiki/Piperidine,
Piperidine | C5H11N – PubChem

Meerovich, Igor published the artcileDirect solid-phase peptide synthesis on chitosan microparticles for targeting tumor cells, Quality Control of 35661-58-6, the publication is Journal of Drug Delivery Science and Technology (2019), 101288, database is CAplus.

An EGFR-targeting peptide with Ala-Glu-Tyr-Leu-Arg sequence was assembled directly onto the surface of spray-dried chitosan microparticles using solid-phase peptide synthesis with Fmoc chem. Both targeted and scrambled peptides were cleaved from chitosan with enzymic digestion, isolated using reversed-phase HPLC, then identified with LC/MS/MS and amino acid anal. Particles with conjugated peptides and fluorescent-labeled were characterized for binding with A549 (cancer) and WI-26 VA4 (normal) lung cells using flow cytometry and confocal microscopy. The purity of peptide synthesis was in the range of 74-77%. The cell binding studies revealed that particles modified with the peptide bind to lung cancer cells 8.3 times higher than the normal lung cells. The binding potential of surface-modified targeted particles to the tumor cells was compared with scrambled and unmodified ones and was found to be significantly different. The binding was 7.3-7.5-fold higher than the scrambled and unmodified particles, resp. Modification of chitosan particles with direct assembly of Ala-Glu-Tyr-Leu-Arg peptide on their surface enhanced their targeting potential to lung cancer cells and could be used as a potential carrier for delivery and therapy. This approach can further be utilized for assembly of other short peptide ligands on micro- or nanoparticulate systems for tumor targeting.

Journal of Drug Delivery Science and Technology published new progress about 35661-58-6. 35661-58-6 belongs to piperidines, auxiliary class Piperidine,Benzene, name is 1-((9H-Fluoren-9-yl)methyl)piperidine, and the molecular formula is C19H21N, Quality Control of 35661-58-6.

Referemce:
https://en.wikipedia.org/wiki/Piperidine,
Piperidine | C5H11N – PubChem

Rink, Hans published the artcileConversion of N^G-urethane protected arginine to ornithine in peptide solid-phase synthesis, Product Details of C19H21N, the publication is Tetrahedron Letters (1984), 25(6), 621-4, database is CAplus.

During solid-phase peptide synthesis, guanidino protection by adamantyloxycarbonyl (Adoc) or Me₃CO₂C (Boc) groups does not effectively prevent guanidino acylation and subsequent partial conversion of arginine residues to ornithine residues when strongly basic conditions are used to remove α-amino protecting groups. Thus, Z-Phe-Ser(CMe₃)-Leu-Ser(CMe₃)-Lys(Boc)-Ile-Phe-Gln-Glu(OCMe₃)-Arg(Adoc)₂-Leu-Arg(Adoc)₂-Arg(Adoc)₂-Lys(Boc)-Glu(OCMe₃)-OCH₂-resin (I, Z = PhCH₂O₂C, CH₂-resin = acid-labile p-benzyloxybenzyl alc. resin) was prepared by the solid-phase method using 9-fluorenyloxycarbonyl (Fmoc) amino acids and then I was cleaved and deblocked to give Z-Phe-Ser-Leu-Ser-Lys-Ile-Phe-Gln-Glu-X-Leu-Orn-Arg-Lys-Glu-OH (X = Orn, Arg). The above arginine to ornithine conversion was confirmed by the following model reactions. Boc-Arg(Adoc)₂-OMe was treated with (Fmoc-Phe)₂O to give arginine II, which was Fmoc-deblocked by piperidine/DMF to give Boc-Orn(Adoc)-OMe, fluorene III, and imidazolinone IV.

Tetrahedron Letters published new progress about 35661-58-6. 35661-58-6 belongs to piperidines, auxiliary class Piperidine,Benzene, name is 1-((9H-Fluoren-9-yl)methyl)piperidine, and the molecular formula is C19H21N, Product Details of C19H21N.

Referemce:
https://en.wikipedia.org/wiki/Piperidine,
Piperidine | C5H11N – PubChem

Knutson, Daniel E. published the artcileImproved scale-up synthesis and purification of clinical asthma candidate MIDD0301, Formula: C19H21N, the publication is Organic Process Research & Development (2020), 24(8), 1467-1476, database is CAplus and MEDLINE.

An improved and scalable synthesis of MIDD0301, a pos. GABAA receptor modulator that is under development as oral and inhaled treatments for asthma was reported. The starting material to generate MIDD0301 is 2-amino-5-bromo-2′-fluorobenzophenone, which has a non-basic nitrogen due to electron withdrawing substituents in ortho and para positions, reducing its reactivity towards activated carboxylic acids. Investigations of peptide coupling reagents on multigram scale resulted in moderate yields due to incomplete conversions. Secondly, basic conditions used for the formation of the seven-member 1,4-diazepine ring resulted in racemization of the chiral center. It was found that neutral conditions comparable to the pKa of the primary amine where sufficient to support the formation of the intramol. imine but did not enable the simultaneous removal of the protecting group. Both difficulties were overcome with the application of the N-carboxyanhydride of D-alanine. Activated in the presence of acid, this compound reacted with non-basic 2-amino-5-bromo-2′-fluorobenzophenone and formed the 1,4-diazepine upon neutralization with triethylamine. Carefully designed workup procedures and divergent solubility of the synthesis intermediates in solvents and solvent combinations were utilized to eliminate the need for column chromatog. To improve compatibility with large scale reactors, temperature-controlled slow addition of reagents generated the imidazodiazepine at -20°C. All intermediates were isolated with a purity of >97% and impurities were identified and quantified. After the final hydrolysis step, MIDD0301 was isolated with a 44% overall yield and purity of 98.9% after recrystallization The enantiomeric excess was higher than 99.0%.

Organic Process Research & Development published new progress about 35661-58-6. 35661-58-6 belongs to piperidines, auxiliary class Piperidine,Benzene, name is 1-((9H-Fluoren-9-yl)methyl)piperidine, and the molecular formula is C19H21N, Formula: C19H21N.

Referemce:
https://en.wikipedia.org/wiki/Piperidine,
Piperidine | C5H11N – PubChem

Torre, Beatriz G. published the artcileRefractive index: The ultimate tool for real-time monitoring of solid-phase peptide synthesis. Greening the process, Computed Properties of 35661-58-6, the publication is Organic Process Research & Development (2021), 25(4), 1047-1053, database is CAplus.

Peptides are the basis of many drugs currently on the market and of more in advanced studies. Most peptides are synthesized using solid-phase peptide synthesis (SPPS). A characteristic of this strategy is that synthetic intermediates are not isolated. In this context, the development of a real-time monitoring method would assure an optimal synthetic process. The refractive index (RI) of a liquid provides key information about its phys. properties and the composition of any solution Here, we provide the first demonstration that the RI is a process anal. tool (PAT) suitable for the real-time monitoring of SPPS. This strategy comprises three steps: coupling, deprotection, and washes, which can be monitored online by refractometry. Given that monitoring capacity helps in the determination of the endpoint of the reactions and the optimization of all synthetic steps, it has a direct impact on the consumption of reagents, solvents, and time, thereby contributing to greener SPPS.

Organic Process Research & Development published new progress about 35661-58-6. 35661-58-6 belongs to piperidines, auxiliary class Piperidine,Benzene, name is 1-((9H-Fluoren-9-yl)methyl)piperidine, and the molecular formula is C13H10O3, Computed Properties of 35661-58-6.

Referemce:
https://en.wikipedia.org/wiki/Piperidine,
Piperidine | C5H11N – PubChem

Yeo, Jet published the artcileLiquid phase peptide synthesis via one-pot nanostar sieving (PEPSTAR), Computed Properties of 35661-58-6, the publication is Angewandte Chemie, International Edition (2021), 60(14), 7786-7795, database is CAplus and MEDLINE.

Herein, a one-pot liquid phase peptide synthesis featuring iterative addition of amino acids to a “nanostar” support, with organic solvent nanofiltration (OSN) for isolation of the growing peptide after each synthesis cycle is reported. A cycle consists of coupling, Fmoc (Fmoc = 9-fluorenylmethoxycarbonyl) removal, then sieving out of the reaction byproducts via nanofiltration in a reactor-separator, or synthesizer apparatus where no phase or material transfers are required between cycles. The three-armed and monodisperse nanostar facilitates both efficient nanofiltration and real-time reaction monitoring of each process cycle. This enabled the synthesis of peptides more efficiently while retaining the full benefits of liquid phase synthesis. PEPSTAR was validated initially with the synthesis of enkephalin-like model penta- and decapeptides, then octreotate amide and finally octreotate. The crude purities compared favorably to vendor produced samples from solid phase synthesis.

Angewandte Chemie, International Edition published new progress about 35661-58-6. 35661-58-6 belongs to piperidines, auxiliary class Piperidine,Benzene, name is 1-((9H-Fluoren-9-yl)methyl)piperidine, and the molecular formula is C15H19BO2, Computed Properties of 35661-58-6.

Referemce:
https://en.wikipedia.org/wiki/Piperidine,
Piperidine | C5H11N – PubChem

Kelly, Richard P. published the artcileβ-Elimination of 9-(dimethylaminomethyl)fluorene; buffer catalysis and pH dependence indicating a zwitterion intermediate, Product Details of C19H21N, the publication is Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999) (1979), 681-9, database is CAplus.

In aqueous NaOH and tertiary amine buffers at 25°, 9-(dimethylaminomethyl)fluorene eliminates Me₂NH to form dibenzofulvene. At 0.02-0.2M HO^–, the reaction is 1st order in HO^– with a rate constant expected of ionization to a fluorenyl anion. At >0.2M the order in HO^– falls, consistent with a change in rate-determining step to loss of the leaving group. At <0.02M the order also falls and in buffer solutions the reaction shows general acid catalysis, as expected of rate-determining attack of HO^– and buffer base on protonated substrate. A stepwise mechanism is proposed with formation of a zwitterion intermediate preceded resp. at high pH by a fluoren-9-yl anion and at low pH by a dimethylammonium cation.

Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999) published new progress about 35661-58-6. 35661-58-6 belongs to piperidines, auxiliary class Piperidine,Benzene, name is 1-((9H-Fluoren-9-yl)methyl)piperidine, and the molecular formula is C19H21N, Product Details of C19H21N.

Referemce:
https://en.wikipedia.org/wiki/Piperidine,
Piperidine | C5H11N – PubChem