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1.
Int J Biol Macromol ; 91: 278-93, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27196367

RESUMO

The post synthesis of Al(3+) or Zr(4+) substituted MCM-48 framework with controlled acidity is challenging because the functional groups exhibiting acidity often jeopardize the framework integrity. Herein, we report the post-synthesis of two hierarchically porous MCM-48 composed of either aluminum (Al(3+)) or zirconium (Zr(4+)) clusters with high throughput. All prepared catalysts have been characterized by HR-TEM, XRD, IR, N2-adsorption, NH3-TPD, TGA and MAS NMR. They exhibit BET surface areas of 597 and 1112m(2)g(-1) for 8.4% Al/MCM-48 and 2.9% Zr/MCM-48, respectively. XRD analysis reveals that the hierarchical porosity of parental MCM-48 is reserved even after incorporation of Al(3+)or Zr(4+). Zr/MCM-48 catalysts are demonstrate a superior performance versus that of Al/MCM-48 and MCM-48 because of the mild (ZrO2) or nil (SiO2) Lewis acidity contributed from Zr-µ2-O group as well as smaller pore sizes suitable for the restriction of unwanted side reactions. The reaction conditions which were affecting the catalytic pyrolysis and final products were gas flow rate, pyrolysis temperature, and catalyst to lignin ratio. A total of 49% of BTX product were obtained over 2.9% Zr/MCM-48 at 600°C. The Lewis acid character was the governing factor which helps in pyrolysis and directly affects the BTX formation.


Assuntos
Lignina/química , Dióxido de Silício/química , Catálise
2.
Nucleosides Nucleotides ; 18(1): 95-111, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10048226

RESUMO

Treatment of the sodium salt of compounds 1, 7 or 12 with chloroethyl methyl ether, 2-chloroethyl toluoylate or 2-(2-chloro ethoxy)ethyl acetate afforded the corresponding derivatives 2, 3, 4, 8, 9, 13 and 14. Ammonolysis of 3, 4, 9 and 14 at room temperature gave the corresponding hydroxyalkyl derivatives 5, 6, 10, 11, and 15, respectively. Alkylation of 2,4-dithiouracil gave 2,4-dialkylthio pyrimidine.


Assuntos
Antivirais/síntese química , Vírus da Hepatite B/efeitos dos fármacos , Tionucleosídeos/síntese química , Replicação Viral/efeitos dos fármacos , Antivirais/química , Antivirais/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Vírus da Hepatite B/fisiologia , Humanos , Indicadores e Reagentes , Estrutura Molecular , Relação Estrutura-Atividade , Tionucleosídeos/química , Tionucleosídeos/farmacologia , Células Tumorais Cultivadas
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