The conditions of colour reaction of 2-(1,3,4-Triazolylazo)-5-Diethylamino-benzoic acid(TZDBA)with vanadium(V) are presented.The results show that the colour reagent reacts with vanadium,and forms a stable purple red ...The conditions of colour reaction of 2-(1,3,4-Triazolylazo)-5-Diethylamino-benzoic acid(TZDBA)with vanadium(V) are presented.The results show that the colour reagent reacts with vanadium,and forms a stable purple red complex in the medium of HCl with pH 2.0. The apparent molar absorptivity is 3 17×10 4L·mol -1 ·cm -1 ,and the maximum absorption wavelength is at 571 nm.Beer’s law is obeyed in the range of 0～20 μ g/25ml for V(V).The method has been used for the direct determination of vanadium in a aluminium alloy sample and a synthetic water sample with satisfactory results.展开更多
Nucleoside reverse transcriptase inhibitors are the only drugs so far approved for the treatment of AIDS. Several nucleoside analogs are potent inhibitors of human immunodeficiency virus(HIV) in cell culture. However,...Nucleoside reverse transcriptase inhibitors are the only drugs so far approved for the treatment of AIDS. Several nucleoside analogs are potent inhibitors of human immunodeficiency virus(HIV) in cell culture. However, in many cases the nucleoside derivatives have a poor affinity for nucleoside kinases. Nucleoside 5′-phosphorothioates is relatively resistant to enzymatic transformations. In this paper, 2′,3′-O-alkoxymethylidene adenosine 5′-thiophosphoramidates were synthesized through a highly efficient approach. The new compounds were characterized by NMR, IR and ESI-MS.展开更多
This paper reports that in the presence of cetyltrimethyl ammonium bromide as phase transfer catalyst,D-glucosamine hydrochloride reacts with 2,4-dinitrophenol to synthesize 1-O-(2’,4’-dinitrophenyl)-2-acetamido-β-...This paper reports that in the presence of cetyltrimethyl ammonium bromide as phase transfer catalyst,D-glucosamine hydrochloride reacts with 2,4-dinitrophenol to synthesize 1-O-(2’,4’-dinitrophenyl)-2-acetamido-β-D-glucoside.Chemical structure of the new compound was confirmed by elemental analysis,IR and UV.展开更多
文摘The conditions of colour reaction of 2-(1,3,4-Triazolylazo)-5-Diethylamino-benzoic acid(TZDBA)with vanadium(V) are presented.The results show that the colour reagent reacts with vanadium,and forms a stable purple red complex in the medium of HCl with pH 2.0. The apparent molar absorptivity is 3 17×10 4L·mol -1 ·cm -1 ,and the maximum absorption wavelength is at 571 nm.Beer’s law is obeyed in the range of 0～20 μ g/25ml for V(V).The method has been used for the direct determination of vanadium in a aluminium alloy sample and a synthetic water sample with satisfactory results.
文摘Nucleoside reverse transcriptase inhibitors are the only drugs so far approved for the treatment of AIDS. Several nucleoside analogs are potent inhibitors of human immunodeficiency virus(HIV) in cell culture. However, in many cases the nucleoside derivatives have a poor affinity for nucleoside kinases. Nucleoside 5′-phosphorothioates is relatively resistant to enzymatic transformations. In this paper, 2′,3′-O-alkoxymethylidene adenosine 5′-thiophosphoramidates were synthesized through a highly efficient approach. The new compounds were characterized by NMR, IR and ESI-MS.
文摘This paper reports that in the presence of cetyltrimethyl ammonium bromide as phase transfer catalyst,D-glucosamine hydrochloride reacts with 2,4-dinitrophenol to synthesize 1-O-(2’,4’-dinitrophenyl)-2-acetamido-β-D-glucoside.Chemical structure of the new compound was confirmed by elemental analysis,IR and UV.
