The copolymerization of DL-LA and 3-BMG was carried out in bulk with stannous 2-ethythexanoate as the catalyst. A series of copolymers with pendant protected groups were obtained and characterized by H-1-NMR and GPC a...The copolymerization of DL-LA and 3-BMG was carried out in bulk with stannous 2-ethythexanoate as the catalyst. A series of copolymers with pendant protected groups were obtained and characterized by H-1-NMR and GPC analysis. The monomer reactivity ratios were evaluated by the Fineman-Ross method and the Kelen-Tudos method and found to be r(BMG)=1.96 and r(LA)=0.37, respectively.展开更多
A novel and efficient method was developed for the liquid-phase synthesis of Nj,4-disubstitutedbenzodiazepine-2,5-diones with 2-chloro-5-nitrobenzoic acid as initiating material via 4 step reactions containing esterif...A novel and efficient method was developed for the liquid-phase synthesis of Nj,4-disubstitutedbenzodiazepine-2,5-diones with 2-chloro-5-nitrobenzoic acid as initiating material via 4 step reactions containing esterifieation, ＂Ulmn reaction＂, acylation, alkylation and cyclization. The reaction conditions were mild and the overall yields of the products ranged from 45% to 71%.展开更多
A series of 4,6,7,8-tetrahydro-2,5-（1H,3H）-quinolinediones was prepared from ethyl-2-cyanoacetate, aromatic aldehydes and 1,3-cyclohexanedione or 5,5-dimethyl-1,3-cyclohexanedione by two steps, the yields were moder...A series of 4,6,7,8-tetrahydro-2,5-（1H,3H）-quinolinediones was prepared from ethyl-2-cyanoacetate, aromatic aldehydes and 1,3-cyclohexanedione or 5,5-dimethyl-1,3-cyclohexanedione by two steps, the yields were moderate to excellent. This method is a new practical promising green strategy to synthesize tetrahydronquinolin-2,5-diones.展开更多
A series of novel copolymers were successfully synthesized by ring-opening polymerization （ROP） of 3 （S）-methyl-morpholine-2,5-dione （MMD） and 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one （MBC） using stan- no...A series of novel copolymers were successfully synthesized by ring-opening polymerization （ROP） of 3 （S）-methyl-morpholine-2,5-dione （MMD） and 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one （MBC） using stan- nous octoate as catalyst. The copolymers were characterized by means of ~H-NMR and FT-IR spectroscopy. Gel permeation chromatography （GPC） test shows that the average-number relative molecular mass and average-weight rela- tive molecular mass slightly increase with the increase of MBC content in feed. The results of differential scanning calorimetry （DSC） demonstrate that the glass transition temperature of copolymers increases with the increase of MBC content in copolymers. The copolymers of MMD and MBC are amorphous copolymers, as indicated by DSC results, while the homopolymer of MMD is semicrystalline.展开更多
The title compound （C19H23NO3） was synthesized by the one-pot reaction ofp-methoxybenzaldehyde, Meldrum＇s acid, dimedone and CH3NH3Cl （NaOAc） in ethanol under microwave irradiation without catalyst and its crysta...The title compound （C19H23NO3） was synthesized by the one-pot reaction ofp-methoxybenzaldehyde, Meldrum＇s acid, dimedone and CH3NH3Cl （NaOAc） in ethanol under microwave irradiation without catalyst and its crystal structure was determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 8.7462（10）, b = 17.7367（19）, c = 11.5959（14） A, β = 110.981（3）°, V= 1679.6（3） A^3, Z = 4, Dc = 1.239 g/cm^3,μ（MoKa） = 0.083 mm^-1, F（000） = 672 and Mr = 313.38. The structure was refined to R = 0.0530 and wR = 0.1216. X-ray analysis reveals that the dihedral angle between plane 1 （N（1）, C（1）, C（2）, C（3）） and plane 2 （C（1）, C（2）, C（6）, C（7）, C（9）） is 3.64°, andt hat between plane 2 and plane 3 （C（11）～C（16）） is 85.33°.展开更多
The cyclization reaction of D-aspartic acid was studied, the carboxyl groups of D-aspartic acid were protected by benzyl alcohol to give compound D-dibenzyl aspartate. Then （4R）-benzyl azetidine-2-one-4-carboxylate ...The cyclization reaction of D-aspartic acid was studied, the carboxyl groups of D-aspartic acid were protected by benzyl alcohol to give compound D-dibenzyl aspartate. Then （4R）-benzyl azetidine-2-one-4-carboxylate and meso-3,6-disubstituted piperazine-2,5-diones were synthesized via intramolecular cyclization and intermolecular cycfization of D-dibenzyl aspartate, respectively, and their structures were confirmed by ^1 H NMR and MS. Both cyclization reaction conditions were also investigated in detail.展开更多
D,L-lactide was prepared from D,L-lactic acid by means of polymerization and depolymerization at low vacuum level.Morpholine-2,5-dione(MD) was synthesized from the cyclization of chloroacetyl glycine which was made fr...D,L-lactide was prepared from D,L-lactic acid by means of polymerization and depolymerization at low vacuum level.Morpholine-2,5-dione(MD) was synthesized from the cyclization of chloroacetyl glycine which was made from chloroacetyl chloride and glycine in the basic condition.A novel copolymer(PLAMD) with D,L-lactide(D,L-LA) and morpholine-2,5-dione(MD) was synthesized using stannous octoate as initiator,and characterized with FT-IR and 1HNMR.The biocompatibility of PLAMD and PLA was investigated by MTT and microscope.The results show that amino acid is introduced into PDLLA main chain.PLAMD has better cell affinity than PLA,so it is a promising biomaterial.展开更多
Osthole is a natural coumarin derivative and has a broad scope of biological activities. Two series of novel fused osthole analogues were designed, and synthesized through a highly efficient microwave-promoted synthet...Osthole is a natural coumarin derivative and has a broad scope of biological activities. Two series of novel fused osthole analogues were designed, and synthesized through a highly efficient microwave-promoted synthetic proto- col via the reaction of 4-hydroxycoumarins and fl-ketoesters. The reaction conditions including solvent, catalyst, microwave power and irradiation time were also optimized. The pyrano[3,2-c]chromene-2,5-diones and furo[3,2-c]- coumarins were obtained through two distinct intramolecular cyclization processes, and the proposed mechanism was also discussed.展开更多
基金This work was supported by the Major State Basic Research Program of China (Grant No. G1999064704).
文摘The copolymerization of DL-LA and 3-BMG was carried out in bulk with stannous 2-ethythexanoate as the catalyst. A series of copolymers with pendant protected groups were obtained and characterized by H-1-NMR and GPC analysis. The monomer reactivity ratios were evaluated by the Fineman-Ross method and the Kelen-Tudos method and found to be r(BMG)=1.96 and r(LA)=0.37, respectively.
基金Supported by the Natural Science Foundation of Hubei Province, China(No.2007ABA031)
文摘A novel and efficient method was developed for the liquid-phase synthesis of Nj,4-disubstitutedbenzodiazepine-2,5-diones with 2-chloro-5-nitrobenzoic acid as initiating material via 4 step reactions containing esterifieation, ＂Ulmn reaction＂, acylation, alkylation and cyclization. The reaction conditions were mild and the overall yields of the products ranged from 45% to 71%.
基金Supported by the National Natural Science Foundation of China(No.20772026)the 2007 Excellent Mid-youth Innova-tive Team Project of the Education Department of Hubei Province, China(No.T200701)
文摘A series of 4,6,7,8-tetrahydro-2,5-（1H,3H）-quinolinediones was prepared from ethyl-2-cyanoacetate, aromatic aldehydes and 1,3-cyclohexanedione or 5,5-dimethyl-1,3-cyclohexanedione by two steps, the yields were moderate to excellent. This method is a new practical promising green strategy to synthesize tetrahydronquinolin-2,5-diones.
基金Supported by Chinese Program for New Century Excellent Talents in University "NCET",Ministry of Education of P.R. China(No.2008DFA51170)
文摘A series of novel copolymers were successfully synthesized by ring-opening polymerization （ROP） of 3 （S）-methyl-morpholine-2,5-dione （MMD） and 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one （MBC） using stan- nous octoate as catalyst. The copolymers were characterized by means of ~H-NMR and FT-IR spectroscopy. Gel permeation chromatography （GPC） test shows that the average-number relative molecular mass and average-weight rela- tive molecular mass slightly increase with the increase of MBC content in feed. The results of differential scanning calorimetry （DSC） demonstrate that the glass transition temperature of copolymers increases with the increase of MBC content in copolymers. The copolymers of MMD and MBC are amorphous copolymers, as indicated by DSC results, while the homopolymer of MMD is semicrystalline.
基金The project was supported by the National Natural Science Foundation of China (No. 20372057), the Natural Science Foundation of Jiangsu Province (No. BK2001142), the Open Foundation of Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry and Chemical Engineering, Suzhou University (JSK 011) and the Key Lab of Biotechnology for Medicinal Plants of Jiangsu Province (01AXL 14)
文摘The title compound （C19H23NO3） was synthesized by the one-pot reaction ofp-methoxybenzaldehyde, Meldrum＇s acid, dimedone and CH3NH3Cl （NaOAc） in ethanol under microwave irradiation without catalyst and its crystal structure was determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 8.7462（10）, b = 17.7367（19）, c = 11.5959（14） A, β = 110.981（3）°, V= 1679.6（3） A^3, Z = 4, Dc = 1.239 g/cm^3,μ（MoKa） = 0.083 mm^-1, F（000） = 672 and Mr = 313.38. The structure was refined to R = 0.0530 and wR = 0.1216. X-ray analysis reveals that the dihedral angle between plane 1 （N（1）, C（1）, C（2）, C（3）） and plane 2 （C（1）, C（2）, C（6）, C（7）, C（9）） is 3.64°, andt hat between plane 2 and plane 3 （C（11）～C（16）） is 85.33°.
基金This work is supported by the National Natural Science Foundation of China （No. 20442004 10576002）.
文摘The cyclization reaction of D-aspartic acid was studied, the carboxyl groups of D-aspartic acid were protected by benzyl alcohol to give compound D-dibenzyl aspartate. Then （4R）-benzyl azetidine-2-one-4-carboxylate and meso-3,6-disubstituted piperazine-2,5-diones were synthesized via intramolecular cyclization and intermolecular cycfization of D-dibenzyl aspartate, respectively, and their structures were confirmed by ^1 H NMR and MS. Both cyclization reaction conditions were also investigated in detail.
基金Project(21107032) supported by the National Natural Science Foundation of China Projects(Y406469, Y4110606) supported by the Natural Science Foundation of Zhejiang Province, China+1 种基金Projects(2008AY2018, 2011AY1048-5, 2011AY1030) supported by the Science Foundation of Jiaxing Science and Technology Bureau,ChinaProject(2009C21003) supported by the Science and Technology Department of Zhejiang Province,China
文摘D,L-lactide was prepared from D,L-lactic acid by means of polymerization and depolymerization at low vacuum level.Morpholine-2,5-dione(MD) was synthesized from the cyclization of chloroacetyl glycine which was made from chloroacetyl chloride and glycine in the basic condition.A novel copolymer(PLAMD) with D,L-lactide(D,L-LA) and morpholine-2,5-dione(MD) was synthesized using stannous octoate as initiator,and characterized with FT-IR and 1HNMR.The biocompatibility of PLAMD and PLA was investigated by MTT and microscope.The results show that amino acid is introduced into PDLLA main chain.PLAMD has better cell affinity than PLA,so it is a promising biomaterial.
文摘Osthole is a natural coumarin derivative and has a broad scope of biological activities. Two series of novel fused osthole analogues were designed, and synthesized through a highly efficient microwave-promoted synthetic proto- col via the reaction of 4-hydroxycoumarins and fl-ketoesters. The reaction conditions including solvent, catalyst, microwave power and irradiation time were also optimized. The pyrano[3,2-c]chromene-2,5-diones and furo[3,2-c]- coumarins were obtained through two distinct intramolecular cyclization processes, and the proposed mechanism was also discussed.
