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Jinmao You - One of the best experts on this subject based on the ideXlab platform.
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fluorescence properties of carbazole n 2 methyl Acetyl Chloride and determination of amino compounds via high performance liquid chromatography with pre column fluorescence derivatization
Journal of Chromatography A, 1999Co-Authors: Jinmao You, Wenjian Lao, Xuejun SunAbstract:A sensitive LC method for the determination of amino compounds with fluorescence detection has been developed. The reaction of fluorescent tagging reagent, namely carbazole-N-(2-methyl)Acetyl Chloride (CMA-Cl), with amino acids is reported. Emission maximum for the CMA derivatives of amino acids is 360 nm (λex=335 nm). In all cases, the derivatives exhibit strong fluorescence, whereas the reagent itself also exhibits fluorescence. It is found that the labelled derivatives using CMA-Cl are very stable; <4% decomposition occurs after heating at 40°C for 24 h in neutral solution. Fluorescence intensity of amino acid derivatives is higher in neutral and alkaline than in acidic solutions. This method, in conjunction with a gradient elution, offers baseline resolution of 18 amino acids including Orn from a linear acetonitrile gradient (here, Asn, Gln and Trp are not tested, the principal reasons: Gln and Asn, in a real sample hydrolysed, have been changed into Glu and Asp; Trp gives as much as 60% loss of its monosubstituted derivative under proposed derivatization conditions.). Separation of derivatives is carried out on a reversed-phase C18 column with good reproducibility. Derivatization and chromatographic conditions are optimized. The relative standard deviations (n=6) for 50 pmol of each amino acid derivative are <4.5%. The detection limits, calculated by the corresponding peak heights (in cm) by injecting successively lower concentrations until a signal-to-noise of 3:1, are 10–65 fmol for the labelled amino acids.
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fluorescence properties of carbazole 9 yl Acetyl Chloride and its application for the simultaneous determination of amino acids and biogenic amines via liquid chromatography with fluorescence detection
Analytica Chimica Acta, 1999Co-Authors: Jinmao You, Haitao Sun, Wenjian LaoAbstract:Abstract A rapid and sensitive derivatization method, using carbazole-9-yl-Acetyl Chloride (CRA-Cl) as derivatization reagent, for the simultaneous determination of amino acids and biogenic amines with pre-column fluorescence derivatization via liquid chromatography is investigated. The wavelength of maximum emission for the CRA derivatives is 365 nm (λex 335 nm). Fluorescence spectra of non-acyl Chloride CRA in the presence of various salts, organic halides and different surfactants are also studied. The quenching constants of NaF, NaCl, NaBr, NaI, and CH3I to CRA are 9.4, 12.6, 40.4, 56.2, and 102 M−1, respectively. Heavy atoms (above 1.0 μM) will seriously interfere with CRA emission spectra tested in the presence of halogen-salts and iodomethane. On the basis of Stern–Volmer equation for static quenching and a solute–micelle interaction linear relationship, the monomer quenching constant K of hexadecyltrimethylammonium bromide (CTMAB) to CRA is 3.0×103 M−1. The binding constants K of micelle of CTMAB and TX-100 to CRA are 5.4×103 M−1 and 2.0×103 M−1, respectively. In addition, in a kinetic analysis of CRA emission intensity (ln Iem) a linear correlation between ln Iem and 1/T was found. The slope of the working curve yields an emission stabilization energy of 17.8 kJ/mol. Derivatization and chromatographic conditions for simultaneous separation of derivatized amino acids and biogenic amines have also been optimized on a reversed-phase C18 column using a binary gradient. Studies on derivatization conditions indicate that primary and secondary amines react very fast with CRA-Cl in alkaline solution to give the corresponding fluorescent derivatives, which exhibit excellent sensitivity and stability. This method, in conjunction with a multi-gradient program, offers a complete resolution for amino acids and biogenic amines. For rapid separation of biogenic amines in plant tissue, an isocratic elution is used. Excellent response linearity is demonstrated over the injected amounts range 50–250 pmol for biogenic amines. The relative standard deviations (n=6) at an analytical concentration of pmol level are
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high performance liquid chromatographic determination of n nitrosoamines by pre column fluorescence derivatization with acridone n Acetyl Chloride
Talanta, 1999Co-Authors: Jinmao You, Xinjun Fan, Wenjian Lao, Qingcun ZhuAbstract:A sensitive high performance liquid chromatographic method for the determination of N-nitrosoamines with pre-column fluorescence derivatization has been developed. N-nitrosoamines are first changed into secondary amines using denitrosation reagent, then react with acridone-N-Acetyl Chloride (ARC-Cl) to produce corresponding secondary amine derivatives, which exhibit a strong fluorescence. Maximum emission for ARC derivatives is 430 nm (lambda(ex) 404 nm). The labelled derivatives are very stable, less than 4% decomposition occurs after heating at 40 degrees C for 24 h. Fluorescence intensities of derivatives are higher in neutral and alkaline than in acidic solutions. This method, in conjunction with a multi-gradient program, offers a baseline resolution of the ARC derivatives from a linear acetonitrile gradient. Separation is carried out on a reverse phase C(18) column. Derivatization and chromatographic conditions are optimized. The relative standard deviation (n=6) at an analytical concentration of 10 pmol of each N-nitroamine is less than 4.5%. The detection limits at the fmol level. The method described is also suitable for analysis of other amino compounds in different biological samples.
Arijit Chakraborty - One of the best experts on this subject based on the ideXlab platform.
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zrocl2 8h2o an efficient lewis acid catalyst for the one pot multicomponent synthesis of β acetamido ketones
Tetrahedron, 2006Co-Authors: Rina Ghosh, Swarupananda Maiti, Arijit Chakraborty, Santu Chakraborty, Alok K MukherjeeAbstract:Abstract Aromatic aldehydes were reacted in one-pot with enolisable ketones, acetonitrile and Acetyl Chloride at ambient temperature in the presence of ZrOCl2·8H2O to furnish the corresponding β-acetamido ketones in very good to excellent yields. X-ray crystallographic analysis of one anti-β-acetamido ketone exhibited a two-dimensional supramolecular framework by a combination of N–H⋯O, C–H⋯O and C–H⋯π (arene) hydrogen bonds.
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facile catalyzed acylation of alcohols phenols amines and thiols based on zrocl2 8h2o and Acetyl Chloride in solution and in solvent free conditions
Tetrahedron Letters, 2005Co-Authors: Rina Ghosh, Swarupananda Maiti, Arijit ChakrabortyAbstract:Abstract Acylation of heteroatoms (O, N and S) with Acetyl Chloride based on the use of a catalytic amount of the moisture stable, inexpensive ZrOCl2·8H2O, proceeds efficiently producing the corresponding acylated products in excellent yields.
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one pot multicomponent synthesis of β acetamido ketones based on bicl3 generated in situ from the procatalyst biocl and Acetyl Chloride
Synlett, 2004Co-Authors: Rina Ghosh, Swarupananda Maiti, Arijit ChakrabortyAbstract:Aromatic aldehydes react in one pot at room temperature with enolizable ketones and acetonitrile in the presence of Acetyl Chloride and catalytic amount of BiOCI producing the corresponding β-acetamido ketones in very high to excellent yields. BiCl 3 generated in situ from BiOCI and Acetyl Chloride catalyzes the multicomponent reaction.
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facile catalyzed acylation of heteroatoms using bicl3 generated in situ from the procatalyst biocl and Acetyl Chloride
Tetrahedron Letters, 2004Co-Authors: Rina Ghosh, Swarupananda Maiti, Arijit ChakrabortyAbstract:Abstract Acylation of a variety of alcohols, phenols, aliphatic and aromatic amines, a thiol and a thiophenol proceeds efficiently using BiCl 3 generated in situ from the procatalyst BiOCl and Acetyl Chloride in a solvent or under solventless conditions, furnishing the corresponding acylated derivatives in very good to excellent yields.
Abu T Khan - One of the best experts on this subject based on the ideXlab platform.
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iron iii Chloride catalyzed convenient one pot synthesis of β acetamido carbonyl compounds
Tetrahedron, 2007Co-Authors: Abu T Khan, Tasneem Parvin, Lokman H ChoudhuryAbstract:Abstract A one-pot multi-component reaction of aldehydes, enolizable ketones or 1,3-dicarbonyls, acetonitrile/benzonitrile, and Acetyl Chloride is described for the preparation of β-acetamido carbonyl compounds using FeCl3·6H2O as a mild, inexpensive, and highly efficient catalyst. The effect of substrate as well as substituent for multi-component reaction versus Knoevenagel condensation is also illustrated. The key features of this methodology are operational simplicity, mild reaction conditions, and good yields.
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cecl3 7h2o an efficient and reusable catalyst for the preparation of β acetamido carbonyl compounds by multi component reactions mcrs
Tetrahedron Letters, 2006Co-Authors: Abu T Khan, Lokman H Choudhury, Tasneem ParvinAbstract:Abstract A convenient method for the preparation of β-acetamido carbonyl compounds is described by multi-component reactions of aromatic aldehydes, enolizable ketones or β-keto esters and acetonitrile in the presence of Acetyl Chloride and 10 mol % CeCl 3 ·7H 2 O at room temperature.
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a highly efficient and useful synthetic protocol for the cleavage of tert butyldimethylsilyl tbs ethers using a catalytic amount of Acetyl Chloride in dry methanol
Synlett, 2003Co-Authors: Abu T Khan, Ejabul MondalAbstract:A wide variety of tert-butyldimethylsilyl (TBS) ethers as well as tert-butyldiphenylsilyl (TBDPS) ethers 1 can be easily deprotected to the corresponding parent hydroxyl compounds 2 by employing catalytic amounts of Acetyl Chloride in dry MeOH at 0 °C to room temperature in good yields. Some of the major advan- tages are mild conditions, high efficiency, high selectivity, high yields, easy operation, and also compatibility with other protecting groups. Furthermore, no Acetylation nor chlorination takes place un- der the experimental conditions.
Wenjian Lao - One of the best experts on this subject based on the ideXlab platform.
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fluorescence properties of carbazole n 2 methyl Acetyl Chloride and determination of amino compounds via high performance liquid chromatography with pre column fluorescence derivatization
Journal of Chromatography A, 1999Co-Authors: Jinmao You, Wenjian Lao, Xuejun SunAbstract:A sensitive LC method for the determination of amino compounds with fluorescence detection has been developed. The reaction of fluorescent tagging reagent, namely carbazole-N-(2-methyl)Acetyl Chloride (CMA-Cl), with amino acids is reported. Emission maximum for the CMA derivatives of amino acids is 360 nm (λex=335 nm). In all cases, the derivatives exhibit strong fluorescence, whereas the reagent itself also exhibits fluorescence. It is found that the labelled derivatives using CMA-Cl are very stable; <4% decomposition occurs after heating at 40°C for 24 h in neutral solution. Fluorescence intensity of amino acid derivatives is higher in neutral and alkaline than in acidic solutions. This method, in conjunction with a gradient elution, offers baseline resolution of 18 amino acids including Orn from a linear acetonitrile gradient (here, Asn, Gln and Trp are not tested, the principal reasons: Gln and Asn, in a real sample hydrolysed, have been changed into Glu and Asp; Trp gives as much as 60% loss of its monosubstituted derivative under proposed derivatization conditions.). Separation of derivatives is carried out on a reversed-phase C18 column with good reproducibility. Derivatization and chromatographic conditions are optimized. The relative standard deviations (n=6) for 50 pmol of each amino acid derivative are <4.5%. The detection limits, calculated by the corresponding peak heights (in cm) by injecting successively lower concentrations until a signal-to-noise of 3:1, are 10–65 fmol for the labelled amino acids.
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fluorescence properties of carbazole 9 yl Acetyl Chloride and its application for the simultaneous determination of amino acids and biogenic amines via liquid chromatography with fluorescence detection
Analytica Chimica Acta, 1999Co-Authors: Jinmao You, Haitao Sun, Wenjian LaoAbstract:Abstract A rapid and sensitive derivatization method, using carbazole-9-yl-Acetyl Chloride (CRA-Cl) as derivatization reagent, for the simultaneous determination of amino acids and biogenic amines with pre-column fluorescence derivatization via liquid chromatography is investigated. The wavelength of maximum emission for the CRA derivatives is 365 nm (λex 335 nm). Fluorescence spectra of non-acyl Chloride CRA in the presence of various salts, organic halides and different surfactants are also studied. The quenching constants of NaF, NaCl, NaBr, NaI, and CH3I to CRA are 9.4, 12.6, 40.4, 56.2, and 102 M−1, respectively. Heavy atoms (above 1.0 μM) will seriously interfere with CRA emission spectra tested in the presence of halogen-salts and iodomethane. On the basis of Stern–Volmer equation for static quenching and a solute–micelle interaction linear relationship, the monomer quenching constant K of hexadecyltrimethylammonium bromide (CTMAB) to CRA is 3.0×103 M−1. The binding constants K of micelle of CTMAB and TX-100 to CRA are 5.4×103 M−1 and 2.0×103 M−1, respectively. In addition, in a kinetic analysis of CRA emission intensity (ln Iem) a linear correlation between ln Iem and 1/T was found. The slope of the working curve yields an emission stabilization energy of 17.8 kJ/mol. Derivatization and chromatographic conditions for simultaneous separation of derivatized amino acids and biogenic amines have also been optimized on a reversed-phase C18 column using a binary gradient. Studies on derivatization conditions indicate that primary and secondary amines react very fast with CRA-Cl in alkaline solution to give the corresponding fluorescent derivatives, which exhibit excellent sensitivity and stability. This method, in conjunction with a multi-gradient program, offers a complete resolution for amino acids and biogenic amines. For rapid separation of biogenic amines in plant tissue, an isocratic elution is used. Excellent response linearity is demonstrated over the injected amounts range 50–250 pmol for biogenic amines. The relative standard deviations (n=6) at an analytical concentration of pmol level are
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high performance liquid chromatographic determination of n nitrosoamines by pre column fluorescence derivatization with acridone n Acetyl Chloride
Talanta, 1999Co-Authors: Jinmao You, Xinjun Fan, Wenjian Lao, Qingcun ZhuAbstract:A sensitive high performance liquid chromatographic method for the determination of N-nitrosoamines with pre-column fluorescence derivatization has been developed. N-nitrosoamines are first changed into secondary amines using denitrosation reagent, then react with acridone-N-Acetyl Chloride (ARC-Cl) to produce corresponding secondary amine derivatives, which exhibit a strong fluorescence. Maximum emission for ARC derivatives is 430 nm (lambda(ex) 404 nm). The labelled derivatives are very stable, less than 4% decomposition occurs after heating at 40 degrees C for 24 h. Fluorescence intensities of derivatives are higher in neutral and alkaline than in acidic solutions. This method, in conjunction with a multi-gradient program, offers a baseline resolution of the ARC derivatives from a linear acetonitrile gradient. Separation is carried out on a reverse phase C(18) column. Derivatization and chromatographic conditions are optimized. The relative standard deviation (n=6) at an analytical concentration of 10 pmol of each N-nitroamine is less than 4.5%. The detection limits at the fmol level. The method described is also suitable for analysis of other amino compounds in different biological samples.
Hamid Reza Shaterian - One of the best experts on this subject based on the ideXlab platform.
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zinc hydrogensulfate as an efficient catalyst for preparation of β amido carbonyl compounds
Chinese Journal of Chemistry, 2009Co-Authors: Hamid Reza Shaterian, Asghar HosseinianAbstract:A one-pot and efficient three-component condensation of benzaldehyde derivatives, enolizable ketones or ketoesters, Acetyl Chloride, and acetonitrile or benzonitrile under ambient conditions in the presence of zinc hydrogensulfate for the synthesis of β-amido carbonyl compounds is described. The simple experimental procedure, high to excellent yields of products and preparation of diastereoselective β-acetamido ketoesters are strong features of the presented method.
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silica supported perchloric acid hclo4 sio2 an efficient catalyst for the preparation of β amido carbonyl compounds using multicomponent reactions
Synthetic Communications, 2008Co-Authors: Hamid Reza Shaterian, Asghar Hosseinian, Majid GhashangAbstract:A new, one-pot, efficient, three-component condensation of benzaldehyde derivatives, enolizable ketones, Acetyl Chloride, and acetonitrile or benzonitrile in the presence of silica-supported perchloric acid as an effective catalyst for the synthesis of β-amido carbonyl compounds is described. The present methodology offers several advantages, such as good yields, short reaction times, and simple workup procedure.
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one pot preparation of β amido ketones esters in a three component condensation reaction using magnesium hydrogensulfate as an effective and reusable catalyst
ChemInform, 2008Co-Authors: Hamid Reza Shaterian, Asghar Hosseinian, Majid GhashangAbstract:A one-pot, three-component condensation of an aryl aldehyde, an enolizable ketone or β-keto ester, Acetyl Chloride, and acetonitrile or benzonitrile in the presence of magnesium hydrogensulfate as ...
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one pot preparation of β amido ketones esters in a three component condensation reaction using magnesium hydrogensulfate as an effective and reusable catalyst
Canadian Journal of Chemistry, 2008Co-Authors: Hamid Reza Shaterian, Asghar Hosseinian, Majid GhashangAbstract:A one-pot, three-component condensation of an aryl aldehyde, an enolizable ketone or β-keto ester, Acetyl Chloride, and acetonitrile or benzonitrile in the presence of magnesium hydrogensulfate as an active, recoverable, and reusable green catalyst is described for the synthesis of β-amido ketones/esters at room temperature. The key features of this methodology are simplicity, mild reaction conditions, and high to excellent yields.Key words: multi-component reaction, magnesium hydrogensulfate, heterogeneous catalyst, β-amido ketone/ester, mild conditions.
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one pot preparation of β amido ketones and esters in four component condensation reaction using ferric hydrogensulfate as effective and reusable catalyst
Arkivoc, 2008Co-Authors: Hamid Reza Shaterian, Hossein Yarahmadi, Majid GhashangAbstract:A new one-pot and efficient four-component condensation of benzaldehyde derivatives, enolizable ketones, Acetyl Chloride and acetonitrile or benzonitrile in the presence of ferric hydrogensulfate as an inexpensive and effective catalyst for the synthesis of β-amido ketones and esters is described. The present methodology offers several advantages, such as good yields, short reaction times and a recyclable catalyst with a very easy work up.