A convenient, efficient and general method has been developed for synthesis of H-phosphonate mono and diesters of AZT and d4T through one-pot reaction of phosphonic acid with AZT or d4T and different alcohols using pi...A convenient, efficient and general method has been developed for synthesis of H-phosphonate mono and diesters of AZT and d4T through one-pot reaction of phosphonic acid with AZT or d4T and different alcohols using pivaloyl chloride as condensing agent under mild conditions.展开更多
N-pivaloyl-Nˊ-（3,4-dichlorophenyl）thiourea （1）： monoclinic, P21/a, a=11.57（1）, b=9.278（8）, c=13.51（1）, β=103.85（1）°, V=1408（2）3 , Z=4, μ=0.598 mm-1 ; N-pivaloyl-N＇-（3,5- dichlorophenyl）thiour...N-pivaloyl-Nˊ-（3,4-dichlorophenyl）thiourea （1）： monoclinic, P21/a, a=11.57（1）, b=9.278（8）, c=13.51（1）, β=103.85（1）°, V=1408（2）3 , Z=4, μ=0.598 mm-1 ; N-pivaloyl-N＇-（3,5- dichlorophenyl）thiourea （2）： monoclinic, P21/a, a=7.176（2）, b=16.441（4）, c=11.923（2）, β=92.48（1）°, V=1405.3（6）3 , Z=4, μ=0.600 mm-1 ; N-pivaloyl-Nˊ-（2,6-dichlorophenyl）thiourea （3）： orthorhombic, Pnma, a=26.79（1）, b=8.780（4）, c=5.955（3）, V=1400.7（11）3 , Z=4, μ=0.601 mm-1 . All three complexes have an intramolecular hydrogen bond between NˊH and the carbonyl oxygen. Solution 1H NMR studies （CDCl3） show the NH resonance considerable downfield for each thiourea and their positions, as well as that of NH, is affected by substituents on the phenyl ring.展开更多
氨基酸稳定氮同位素(δ^(15)N)分析能准确有效地评估生物体的营养级以及氮在食物链中的流动。本研究优化了氨基酸氮同位素的分析方法:样品在酸性条件下水解后,释放出的蛋白质氨基酸经阳离子交换树脂纯化后,衍生为对应的N-新戊酰基,O-异...氨基酸稳定氮同位素(δ^(15)N)分析能准确有效地评估生物体的营养级以及氮在食物链中的流动。本研究优化了氨基酸氮同位素的分析方法:样品在酸性条件下水解后,释放出的蛋白质氨基酸经阳离子交换树脂纯化后,衍生为对应的N-新戊酰基,O-异丙醇(N-pivaloyl-isopropyl,NPP)酯,利用气相色谱-燃烧-同位素比值质谱仪(Gas chromatography-combustion-isotope ratio mass spectrometry,GC-C-IRMS)测定其δ^(15)N。经非极性气相色谱柱DB-5ms分离后,13种氨基酸NPP酯衍生物均可得到良好的基线分离。在样品量不低于20 ng N条件下,GC-C-IRMS方法的精密度优于1‰,测得的δ^(15)N值与EA-IRMS法测得的δ^(15)N值没有明显差异。阳离子树脂纯化前后各氨基酸δ^(15)N值差异低于1‰,表明没有产生明显的同位素分馏。采用本方法成功地估算了阿哈湖生态系统中常见水生生物的营养级,可作为研究氨基酸代谢以及生态系统特征的新方法。展开更多
Synthesis of the title compound was carried out by base-catalyzed cyclization of 1-pivaloyl-3-(2-chloro-4-nitrophenyl) thiourea with α-bromoacetone produced in situ. The structure was confirmed by the spectroscopic a...Synthesis of the title compound was carried out by base-catalyzed cyclization of 1-pivaloyl-3-(2-chloro-4-nitrophenyl) thiourea with α-bromoacetone produced in situ. The structure was confirmed by the spectroscopic and elemental analysis and single crystal X-ray diffraction data. It crystallizes in the triclinic space group P-1 with unit cell dime sions a = 8.7137(10), b = 10.2010(14), c = 10.6593(13), α = 62.671(9), β = 82.701(10), γ = 79.762(10), V = 827.21(8) ?3, Z = 2.展开更多
合成了一种二糖薯蓣皂苷。本文在实现6′-O-Piv-β-D-半乳糖薯蓣皂苷4制备的基础上,通过与葡萄糖给体9进行区域选择性糖苷化反应和乙酰化反应得到化合物7,通过解析7的1 H NMR,13 C NMR,1 H-1 H COSY,HMQC,HM-BC谱图,确定了化合物4选择...合成了一种二糖薯蓣皂苷。本文在实现6′-O-Piv-β-D-半乳糖薯蓣皂苷4制备的基础上,通过与葡萄糖给体9进行区域选择性糖苷化反应和乙酰化反应得到化合物7,通过解析7的1 H NMR,13 C NMR,1 H-1 H COSY,HMQC,HM-BC谱图,确定了化合物4选择性糖苷化的位点是其2′-OH,最后经脱除保护基得到二糖皂苷8。展开更多
基金Project supported by Excellent Dissertation Foundation by the Chinese Ministry of Education (No. 200222).
文摘A convenient, efficient and general method has been developed for synthesis of H-phosphonate mono and diesters of AZT and d4T through one-pot reaction of phosphonic acid with AZT or d4T and different alcohols using pivaloyl chloride as condensing agent under mild conditions.
基金the Quaid-I-Azam University,Islamabad,Pakistan for Post-doctoral Fellowship and financial support
文摘N-pivaloyl-Nˊ-（3,4-dichlorophenyl）thiourea （1）： monoclinic, P21/a, a=11.57（1）, b=9.278（8）, c=13.51（1）, β=103.85（1）°, V=1408（2）3 , Z=4, μ=0.598 mm-1 ; N-pivaloyl-N＇-（3,5- dichlorophenyl）thiourea （2）： monoclinic, P21/a, a=7.176（2）, b=16.441（4）, c=11.923（2）, β=92.48（1）°, V=1405.3（6）3 , Z=4, μ=0.600 mm-1 ; N-pivaloyl-Nˊ-（2,6-dichlorophenyl）thiourea （3）： orthorhombic, Pnma, a=26.79（1）, b=8.780（4）, c=5.955（3）, V=1400.7（11）3 , Z=4, μ=0.601 mm-1 . All three complexes have an intramolecular hydrogen bond between NˊH and the carbonyl oxygen. Solution 1H NMR studies （CDCl3） show the NH resonance considerable downfield for each thiourea and their positions, as well as that of NH, is affected by substituents on the phenyl ring.
文摘氨基酸稳定氮同位素(δ^(15)N)分析能准确有效地评估生物体的营养级以及氮在食物链中的流动。本研究优化了氨基酸氮同位素的分析方法:样品在酸性条件下水解后,释放出的蛋白质氨基酸经阳离子交换树脂纯化后,衍生为对应的N-新戊酰基,O-异丙醇(N-pivaloyl-isopropyl,NPP)酯,利用气相色谱-燃烧-同位素比值质谱仪(Gas chromatography-combustion-isotope ratio mass spectrometry,GC-C-IRMS)测定其δ^(15)N。经非极性气相色谱柱DB-5ms分离后,13种氨基酸NPP酯衍生物均可得到良好的基线分离。在样品量不低于20 ng N条件下,GC-C-IRMS方法的精密度优于1‰,测得的δ^(15)N值与EA-IRMS法测得的δ^(15)N值没有明显差异。阳离子树脂纯化前后各氨基酸δ^(15)N值差异低于1‰,表明没有产生明显的同位素分馏。采用本方法成功地估算了阿哈湖生态系统中常见水生生物的营养级,可作为研究氨基酸代谢以及生态系统特征的新方法。
文摘Synthesis of the title compound was carried out by base-catalyzed cyclization of 1-pivaloyl-3-(2-chloro-4-nitrophenyl) thiourea with α-bromoacetone produced in situ. The structure was confirmed by the spectroscopic and elemental analysis and single crystal X-ray diffraction data. It crystallizes in the triclinic space group P-1 with unit cell dime sions a = 8.7137(10), b = 10.2010(14), c = 10.6593(13), α = 62.671(9), β = 82.701(10), γ = 79.762(10), V = 827.21(8) ?3, Z = 2.
文摘合成了一种二糖薯蓣皂苷。本文在实现6′-O-Piv-β-D-半乳糖薯蓣皂苷4制备的基础上,通过与葡萄糖给体9进行区域选择性糖苷化反应和乙酰化反应得到化合物7,通过解析7的1 H NMR,13 C NMR,1 H-1 H COSY,HMQC,HM-BC谱图,确定了化合物4选择性糖苷化的位点是其2′-OH,最后经脱除保护基得到二糖皂苷8。
