Ozone mediated nitration of chlorobenzene with nitrogen dioxide over solid acid catalysts is expected to be a green process. The reaction was carried out at ca . 0 ℃. It was found that the solid acid catalysts of SO ...Ozone mediated nitration of chlorobenzene with nitrogen dioxide over solid acid catalysts is expected to be a green process. The reaction was carried out at ca . 0 ℃. It was found that the solid acid catalysts of SO 2- 4/TiO 2 and SO 2- 4/ZrO 2 and a series of SO 2- 4/TiO 2 ZrO 2 catalysts exhibited a fairly good activity for the nitration reaction, whereas SO 2- 4/TiO 2 ZrO 2(atomic ratio 1∶1) gives yield of 62 4% and SO 2- 4/TiO 2 ZrO 2(molar ratio 3∶1) shows a good para selectivity in CH 2Cl 2 solvent. The ortho para isomer ratios( ortho/para ) of the nitration products were varied in range from 1 11 to 0 36. This phenomenon is interpreted in terms of acid amount and acid strength of solid acid catalysts.展开更多
To improve the therapeutic effect of rhaponticin （RHA）, a folate receptor （FR） targeted RHA prodrug was designed and regioselectively synthesized by utilizing a hydrophilic peptide spacer linked to folic acid （FA...To improve the therapeutic effect of rhaponticin （RHA）, a folate receptor （FR） targeted RHA prodrug was designed and regioselectively synthesized by utilizing a hydrophilic peptide spacer linked to folic acid （FA） via a releasable disulfide linker. A series of biological evaluation was investigated in vitro and in vivo. The positive results of biological investigations warrant further preclinical study before this novel targeted chemotherapeutic is considered for clinical investigation.展开更多
In the presence of catalytic amount of cesium hydroxide the hydrothiolation of alkynyl selenides occurred at room temperature in DMF under nitrogen atmosphere to give exclusive（Z）-1-organoseleno-2-arylthio-1-alkene ...In the presence of catalytic amount of cesium hydroxide the hydrothiolation of alkynyl selenides occurred at room temperature in DMF under nitrogen atmosphere to give exclusive（Z）-1-organoseleno-2-arylthio-1-alkene in excellent yields.It could provide a new and expedient way for the preparation of（Z）-1-arylseleno-2-arylthio-1-alkene.展开更多
A simple and regioselective synthesis of 2-chloro-3-formyl-l,8-naphthyridine （1） through V ilsmeier-Haack cyclization of N-（pyridine-2-yl） acetamide has been reported. The reaction of compound （1） with sodium su...A simple and regioselective synthesis of 2-chloro-3-formyl-l,8-naphthyridine （1） through V ilsmeier-Haack cyclization of N-（pyridine-2-yl） acetamide has been reported. The reaction of compound （1） with sodium sulphide gives thione （2） and the reaction of compound （1） with Na2S/DMF followed by reaction with alkyl halide in one pot afforded thioether （3 and 4）. New naphthyridone （5） was synthesized from the action of acetic acid and POCI3 in compound （1）. The condensation of compounds （1 and 8） with hydroxylamine and aniline leads to the formation of compounds （6, 7 and 9）. The 2-chloro-3-formyl-l,8-naphthyridine was treated with sodium azide underwent cyclization to afford tetrazolo （l,5-a） （l,8-naphthyridine-4-carbaldehyde （8）. The azitidinone （10 and 12） and thioazolidinone （11 and 13） were synthesized from shift base intermediates by using chloroacetyl chloride and thioglycolic acid. The formyl group in compound （1） is subjected to cyano （14） and 3-alkoxycarbonyl （15）, respectively. The ester （15） was treated with hydrazine hydrate in ethanol to give acid hydrazide （16） then converted to thio semicarbazide （17） by their reaction with ammonium thiocyanate. New thiadiazolo （18）, triazolo （19） and oxadiazolo （20） have been prepared. The structures of synthesized compounds have been confirmed by suitable spectroscopic techniques such as IR （infrared spectrometry） and ^1H NMR （proton nuclear magnetic resonance）.展开更多
3-Iodoindole N-carboximidamides and N-carboximidoates 4 were prepared regioselectively via a sequential aza-Wittig/iodine induced cyclization, starting from easily accessible 2-alkynylphenyl iminophosphorane, isocyana...3-Iodoindole N-carboximidamides and N-carboximidoates 4 were prepared regioselectively via a sequential aza-Wittig/iodine induced cyclization, starting from easily accessible 2-alkynylphenyl iminophosphorane, isocyanates, various nucleophiles and iodine.展开更多
文摘Ozone mediated nitration of chlorobenzene with nitrogen dioxide over solid acid catalysts is expected to be a green process. The reaction was carried out at ca . 0 ℃. It was found that the solid acid catalysts of SO 2- 4/TiO 2 and SO 2- 4/ZrO 2 and a series of SO 2- 4/TiO 2 ZrO 2 catalysts exhibited a fairly good activity for the nitration reaction, whereas SO 2- 4/TiO 2 ZrO 2(atomic ratio 1∶1) gives yield of 62 4% and SO 2- 4/TiO 2 ZrO 2(molar ratio 3∶1) shows a good para selectivity in CH 2Cl 2 solvent. The ortho para isomer ratios( ortho/para ) of the nitration products were varied in range from 1 11 to 0 36. This phenomenon is interpreted in terms of acid amount and acid strength of solid acid catalysts.
基金supported by the National Scientific Foundation of China(No81001622)
文摘To improve the therapeutic effect of rhaponticin （RHA）, a folate receptor （FR） targeted RHA prodrug was designed and regioselectively synthesized by utilizing a hydrophilic peptide spacer linked to folic acid （FA） via a releasable disulfide linker. A series of biological evaluation was investigated in vitro and in vivo. The positive results of biological investigations warrant further preclinical study before this novel targeted chemotherapeutic is considered for clinical investigation.
基金Natural Science Foundation of Hunan(No.2009NK3162)National Natural Science Foundation of China(No.21003040,20372020) for financial support
文摘In the presence of catalytic amount of cesium hydroxide the hydrothiolation of alkynyl selenides occurred at room temperature in DMF under nitrogen atmosphere to give exclusive（Z）-1-organoseleno-2-arylthio-1-alkene in excellent yields.It could provide a new and expedient way for the preparation of（Z）-1-arylseleno-2-arylthio-1-alkene.
文摘A simple and regioselective synthesis of 2-chloro-3-formyl-l,8-naphthyridine （1） through V ilsmeier-Haack cyclization of N-（pyridine-2-yl） acetamide has been reported. The reaction of compound （1） with sodium sulphide gives thione （2） and the reaction of compound （1） with Na2S/DMF followed by reaction with alkyl halide in one pot afforded thioether （3 and 4）. New naphthyridone （5） was synthesized from the action of acetic acid and POCI3 in compound （1）. The condensation of compounds （1 and 8） with hydroxylamine and aniline leads to the formation of compounds （6, 7 and 9）. The 2-chloro-3-formyl-l,8-naphthyridine was treated with sodium azide underwent cyclization to afford tetrazolo （l,5-a） （l,8-naphthyridine-4-carbaldehyde （8）. The azitidinone （10 and 12） and thioazolidinone （11 and 13） were synthesized from shift base intermediates by using chloroacetyl chloride and thioglycolic acid. The formyl group in compound （1） is subjected to cyano （14） and 3-alkoxycarbonyl （15）, respectively. The ester （15） was treated with hydrazine hydrate in ethanol to give acid hydrazide （16） then converted to thio semicarbazide （17） by their reaction with ammonium thiocyanate. New thiadiazolo （18）, triazolo （19） and oxadiazolo （20） have been prepared. The structures of synthesized compounds have been confirmed by suitable spectroscopic techniques such as IR （infrared spectrometry） and ^1H NMR （proton nuclear magnetic resonance）.
文摘3-Iodoindole N-carboximidamides and N-carboximidoates 4 were prepared regioselectively via a sequential aza-Wittig/iodine induced cyclization, starting from easily accessible 2-alkynylphenyl iminophosphorane, isocyanates, various nucleophiles and iodine.
