The experimental results of Benzyl Ntertbutyloxycarbonylβcyclohexylaspartate(Ⅰ)were reported in this paper.Starting from cheap and accessible Laspartic acid,the key intermediate of βcyclohexyl Ntertbuty...The experimental results of Benzyl Ntertbutyloxycarbonylβcyclohexylaspartate(Ⅰ)were reported in this paper.Starting from cheap and accessible Laspartic acid,the key intermediate of βcyclohexyl Ntertbutyloxycarbonylaspartate(Ⅱ)was prepared by esterification of aspartic acid via cyclohexanol catalyzed by sulfuric acid and further acylation via Boc2O.The synthesis of the title compound of(Ⅰ)was performed by benzylization of(Ⅱ)through benzyl bromide.The method is facile and the yield is higher than that in literatures.The structures of these compounds were verified by1H NMR and mp.,or by the corresponding authentic compounds.The discussion of the preparative conditions of Ⅰ and Ⅱ was also given.展开更多
Based on a strategy of ground-state destabilisation of the N—C bond,a general protocol for the esterification of amides with carbohydrates was reported.This protocol offers mild reaction conditions,excellent yields,a...Based on a strategy of ground-state destabilisation of the N—C bond,a general protocol for the esterification of amides with carbohydrates was reported.This protocol offers mild reaction conditions,excellent yields,and broad substrate compatibility,thereby demonstrating great potential for the synthesis of glycoconjugates.Additionally,this method provides an alternative approach for addressing the challenging task of esterifying sterically hindered secondary hydroxyl group of carbohydrates and paving the way for advancements in carbohydrate-based pharmaceuticals.展开更多
The syntheses of N-Methyl-14C benzyl amine and N-Methyl-14C benzyl nitrosamine are reported. Specific activities were approximately 920 MBq/mmol. Chemical and radiochemical purity checked by HPLC were more than 95%.
New metal complexes of N-benzyl-N-nitrosohy-droxylamine (BNHA) are isolated and characterized by elemental analysis, IR and UV-VIS spectroscopy. Spectrophotometric titration of aqueous solutions of BNHА by salts of s...New metal complexes of N-benzyl-N-nitrosohy-droxylamine (BNHA) are isolated and characterized by elemental analysis, IR and UV-VIS spectroscopy. Spectrophotometric titration of aqueous solutions of BNHА by salts of some transition metals allowed to calculate the composition and formation constants of the metal complexes. The crystal structure of Cu (BNHА)2 is studied by X-ray diffraction. The Cu atom is coordinated by four O atoms of two bidentate ligands, which close 5-membered chelate rings. The N-O (1.306 ? - 1.320 ?) and N-N (1.274?? and 1.275? ) bond lengths indicate that π electrons are delocalized over the chelating groups. Complexes form stacks with intermolecular Cu…N contacts equal to 3.118?? and 3.306 ?.展开更多
文摘The experimental results of Benzyl Ntertbutyloxycarbonylβcyclohexylaspartate(Ⅰ)were reported in this paper.Starting from cheap and accessible Laspartic acid,the key intermediate of βcyclohexyl Ntertbutyloxycarbonylaspartate(Ⅱ)was prepared by esterification of aspartic acid via cyclohexanol catalyzed by sulfuric acid and further acylation via Boc2O.The synthesis of the title compound of(Ⅰ)was performed by benzylization of(Ⅱ)through benzyl bromide.The method is facile and the yield is higher than that in literatures.The structures of these compounds were verified by1H NMR and mp.,or by the corresponding authentic compounds.The discussion of the preparative conditions of Ⅰ and Ⅱ was also given.
基金Supported by Grants from the National Natural Science Foundation of China,No.81302906Beijing Natural Science Foundation,No.7144190New Teacher Fund for Doctor Stations of Ministry of Education of China,No.20131107120019
文摘AIM: To evaluate the significance of KL-6/MUC1 (a type of MUC1) glycosylation in pancreatic cancer progression.
文摘Based on a strategy of ground-state destabilisation of the N—C bond,a general protocol for the esterification of amides with carbohydrates was reported.This protocol offers mild reaction conditions,excellent yields,and broad substrate compatibility,thereby demonstrating great potential for the synthesis of glycoconjugates.Additionally,this method provides an alternative approach for addressing the challenging task of esterifying sterically hindered secondary hydroxyl group of carbohydrates and paving the way for advancements in carbohydrate-based pharmaceuticals.
文摘The syntheses of N-Methyl-14C benzyl amine and N-Methyl-14C benzyl nitrosamine are reported. Specific activities were approximately 920 MBq/mmol. Chemical and radiochemical purity checked by HPLC were more than 95%.
文摘New metal complexes of N-benzyl-N-nitrosohy-droxylamine (BNHA) are isolated and characterized by elemental analysis, IR and UV-VIS spectroscopy. Spectrophotometric titration of aqueous solutions of BNHА by salts of some transition metals allowed to calculate the composition and formation constants of the metal complexes. The crystal structure of Cu (BNHА)2 is studied by X-ray diffraction. The Cu atom is coordinated by four O atoms of two bidentate ligands, which close 5-membered chelate rings. The N-O (1.306 ? - 1.320 ?) and N-N (1.274?? and 1.275? ) bond lengths indicate that π electrons are delocalized over the chelating groups. Complexes form stacks with intermolecular Cu…N contacts equal to 3.118?? and 3.306 ?.
