In an attempt to find new antitumor agents,a novel class of chromone compounds with a benzimidazole or a benzoxazole ring in positions 2 or 6 were synthesized via condensation in polyphosphoric acid(PPA) by using chro...In an attempt to find new antitumor agents,a novel class of chromone compounds with a benzimidazole or a benzoxazole ring in positions 2 or 6 were synthesized via condensation in polyphosphoric acid(PPA) by using chromone acids as the starting materials. During the preparation process,it was found that PPA could cleave the chromone ring to produce a ring-opening compound(6). The molar ratio of the chromone compound(5) to the ring-opening compound(6) varied with the change of reaction temperature and time. Based on MTT protocol,the antitumor activity of each of the compounds obtained was evaluated against three human cancer cell lines: KB(oral epidermal),A2780(ovary) and Bel7402(liver). The IC_ 50 varied from 54.7 μmol/L to more than 180 μmol/L.展开更多
In order to study the chemical modification mechanism and rheological properties of polyphosphoric acid (PPA)-modified asphalt,asphalt modified with different PPA contents were characterized by four-component test,ato...In order to study the chemical modification mechanism and rheological properties of polyphosphoric acid (PPA)-modified asphalt,asphalt modified with different PPA contents were characterized by four-component test,atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR).In the test,changes in asphalt chemical composition and colloidal structure were analyzed for different PPA contents,and infrared spectra were fitted with a Gaussian function.The reaction mechanism of PPA and matrix asphalt was also discussed.Based on dynamic shear rheometer (DSR) test and bending beam rheometer (BBR) test,rheological index G~*/sinδ and S/m were used to evaluate the modification effect of PPA on asphalt.The results show that,with an increase in PPA content,both large and small honeycomb structures increased in the three-dimensional topography seen in the atomic force microscope (AFM).In a certain space range,some of the micelles in the asphalt are connected each other to form interlocking skeleton structures,and locally form dense spatial network structures.The added PPA does not chemically react with the functional groups in the functional-group area of the infrared spectra (3 100-2 750 cm^(-1),1 800-1 330 cm^(-1)),and the structure is very stable.However,there is an obvious new absorption peak below 1 330 cm^(-1) in the fingerprint area,that is,the chemical reaction between PPA and the matrix asphalt generates a new compound,inorganic phosphate.Infrared spectra of PPA-modified asphalt with different contents were fitted by a Gaussian function,which makes up for the limitation that the absorption intensity information of each superimposed functional group cannot be obtained directly from the original infrared spectra.Results of this qualitative analysis were further verified by quantitative analysis.The addition of PPA can effectively improve the high and low-temperature performance of asphalt,and the lower the temperature is in the negative temperature zone,the more obvious the improvement is.When PPA content is more than 1%,the improvement of asphalt low-temperature performance is not obvious.展开更多
Cellulose,being as the most abundant nature polymer material and the most promising oil substitute,attracts more and more interests.A new cellulose dissolution system,phosphoric acid(PA)/polyphosphoric acid(PPA) solve...Cellulose,being as the most abundant nature polymer material and the most promising oil substitute,attracts more and more interests.A new cellulose dissolution system,phosphoric acid(PA)/polyphosphoric acid(PPA) solvent,was investigated in this study.It had been found that a larger cellulose solid content could be dissolved quickly in a hypothermic situation.By evaluating the stability of regenerated cellulose film and the formation of anisotropic solution,the dissolution behavior of cellulose was investigated.Wide-angle X-ray diffraction(WAXD) and Fourier transform infrared spectroscopy(FT-IR) were employed to characterize the crystalline structure and morphology of regenerated cellulose.The measurement results revealed a transition from cellulose-Ⅰ of raw cellulose to cellulose-Ⅱ of regenerated cellulose and a decrease of crystallinity of cellulose after dissolved.This was attributed to the interaction between cellulose and acid solvent,which leaded to the breakage of cellulose intra-and inter-molecule hydrogen bonds and the conformation change of cellulose C6-OH.Moreover,the formation process of cellulose liquid crystal solution was illustrated by polarized light microscope(PLM).That may be induced by the rearranging movement of the cellulose macromolecular chains.展开更多
Cyclization of 2-methoxy-6-benzyloxy acetophenone hydrazone gave 3-methyl-4-meth- oxy indazole and 3-methyl-4-methoxy-7-benzyl indazole in the presence of polyphosphoric acid (PPA).The hydrazone was probably converted...Cyclization of 2-methoxy-6-benzyloxy acetophenone hydrazone gave 3-methyl-4-meth- oxy indazole and 3-methyl-4-methoxy-7-benzyl indazole in the presence of polyphosphoric acid (PPA).The hydrazone was probably converted to 2-hydroxy-6-methoxy acetophenone hydra- zone and 2-hydroxy-3-benzyl-6-methoxy acetophenone hydrazone followed by cyclization to the corresponding indazoles in acidic conditions.Cyelization of 2-methoxy-6-(halo or alkyl or aryl benzyloxy)acetophenone hydrazones gave similar products.Cyclization of 2-methoxy-6- (p-nitrobenzyloxy)acetophenone hydrazone gave 2-(p-nitrophenyl)-3-methyl-4-methoxy benzo- furan and 3-methyl-4-methoxy indazole while 2-methoxy-6-(m-nitrobenzyloxy)acetophenone hydrazone gave 3-methyl-4-methoxy indazole,3-methyl-4-methoxy-7-(m-nitrophenyl)indazole and 3-methyl-4-(m-nitrobenzyloxy)indazole.展开更多
Silica gel-supported polyphosphoric acid （PPA-SiO2） was found to be an efficient catalyst for the one-pot four-component Hantzsch condensation reaction of aryl aldehydes, dimedone, ethyl acetoacetate and ammonium ac...Silica gel-supported polyphosphoric acid （PPA-SiO2） was found to be an efficient catalyst for the one-pot four-component Hantzsch condensation reaction of aryl aldehydes, dimedone, ethyl acetoacetate and ammonium acetate to afford the corresponding polyhydroquinoline derivatives in high yields. The main advantages of the present approach are short reaction times, clean reaction profiles, simple experimental and workup procedures.展开更多
In this study,6-chloro-4-hydroxy-2-quinolone and 6-flouro-4-hydroxy-2-quinolone were synthesized from corresponding dianilides.These compounds were coupled with some diazotized aromatic amines to give the correspondin...In this study,6-chloro-4-hydroxy-2-quinolone and 6-flouro-4-hydroxy-2-quinolone were synthesized from corresponding dianilides.These compounds were coupled with some diazotized aromatic amines to give the corresponding azo disperse dyes.The structures of the quinolone derivatives and new azo dyes were confirmed by UV-vis,FT-IR,;H NMR and elemental analysis.展开更多
A facile synthesis of a series of new quinoline-8-carbaldehyde compounds, namely 8-formyl-2- （phenoxymethyl）quinoline-3-carboxylic acids （4a--4h） and 13-oxo-6,13-dihydro[1]benzoxepino[3,4-b]quinoline- 8-carbaldehy...A facile synthesis of a series of new quinoline-8-carbaldehyde compounds, namely 8-formyl-2- （phenoxymethyl）quinoline-3-carboxylic acids （4a--4h） and 13-oxo-6,13-dihydro[1]benzoxepino[3,4-b]quinoline- 8-carbaldehyde （5a--5g） is described, involving the one-pot synthesis reaction of ethyl 2-（chloromethyl）-8- formylquinoline-3-carboxylate （3） with substituted phenols followed by the intramolecular cyclization reaction via the treatment with polyphosphoric acid （PPA）. Quinoline-8-carbaldehydes 4a--4h and 5a--5g are novel and their structures were supported by IR, IH NMR, 13C NMR, MS and elemental analysis.展开更多
文摘In an attempt to find new antitumor agents,a novel class of chromone compounds with a benzimidazole or a benzoxazole ring in positions 2 or 6 were synthesized via condensation in polyphosphoric acid(PPA) by using chromone acids as the starting materials. During the preparation process,it was found that PPA could cleave the chromone ring to produce a ring-opening compound(6). The molar ratio of the chromone compound(5) to the ring-opening compound(6) varied with the change of reaction temperature and time. Based on MTT protocol,the antitumor activity of each of the compounds obtained was evaluated against three human cancer cell lines: KB(oral epidermal),A2780(ovary) and Bel7402(liver). The IC_ 50 varied from 54.7 μmol/L to more than 180 μmol/L.
基金Funded by National Natural Science Foundation of China(No.11962024)Inner Mongolia Transportation Technology Project(No.NJ-2014-9)Research Fund for the Doctoral Program of Higher Education of China(RFDP)(No.BS2020042)。
文摘In order to study the chemical modification mechanism and rheological properties of polyphosphoric acid (PPA)-modified asphalt,asphalt modified with different PPA contents were characterized by four-component test,atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR).In the test,changes in asphalt chemical composition and colloidal structure were analyzed for different PPA contents,and infrared spectra were fitted with a Gaussian function.The reaction mechanism of PPA and matrix asphalt was also discussed.Based on dynamic shear rheometer (DSR) test and bending beam rheometer (BBR) test,rheological index G~*/sinδ and S/m were used to evaluate the modification effect of PPA on asphalt.The results show that,with an increase in PPA content,both large and small honeycomb structures increased in the three-dimensional topography seen in the atomic force microscope (AFM).In a certain space range,some of the micelles in the asphalt are connected each other to form interlocking skeleton structures,and locally form dense spatial network structures.The added PPA does not chemically react with the functional groups in the functional-group area of the infrared spectra (3 100-2 750 cm^(-1),1 800-1 330 cm^(-1)),and the structure is very stable.However,there is an obvious new absorption peak below 1 330 cm^(-1) in the fingerprint area,that is,the chemical reaction between PPA and the matrix asphalt generates a new compound,inorganic phosphate.Infrared spectra of PPA-modified asphalt with different contents were fitted by a Gaussian function,which makes up for the limitation that the absorption intensity information of each superimposed functional group cannot be obtained directly from the original infrared spectra.Results of this qualitative analysis were further verified by quantitative analysis.The addition of PPA can effectively improve the high and low-temperature performance of asphalt,and the lower the temperature is in the negative temperature zone,the more obvious the improvement is.When PPA content is more than 1%,the improvement of asphalt low-temperature performance is not obvious.
文摘Cellulose,being as the most abundant nature polymer material and the most promising oil substitute,attracts more and more interests.A new cellulose dissolution system,phosphoric acid(PA)/polyphosphoric acid(PPA) solvent,was investigated in this study.It had been found that a larger cellulose solid content could be dissolved quickly in a hypothermic situation.By evaluating the stability of regenerated cellulose film and the formation of anisotropic solution,the dissolution behavior of cellulose was investigated.Wide-angle X-ray diffraction(WAXD) and Fourier transform infrared spectroscopy(FT-IR) were employed to characterize the crystalline structure and morphology of regenerated cellulose.The measurement results revealed a transition from cellulose-Ⅰ of raw cellulose to cellulose-Ⅱ of regenerated cellulose and a decrease of crystallinity of cellulose after dissolved.This was attributed to the interaction between cellulose and acid solvent,which leaded to the breakage of cellulose intra-and inter-molecule hydrogen bonds and the conformation change of cellulose C6-OH.Moreover,the formation process of cellulose liquid crystal solution was illustrated by polarized light microscope(PLM).That may be induced by the rearranging movement of the cellulose macromolecular chains.
文摘Cyclization of 2-methoxy-6-benzyloxy acetophenone hydrazone gave 3-methyl-4-meth- oxy indazole and 3-methyl-4-methoxy-7-benzyl indazole in the presence of polyphosphoric acid (PPA).The hydrazone was probably converted to 2-hydroxy-6-methoxy acetophenone hydra- zone and 2-hydroxy-3-benzyl-6-methoxy acetophenone hydrazone followed by cyclization to the corresponding indazoles in acidic conditions.Cyelization of 2-methoxy-6-(halo or alkyl or aryl benzyloxy)acetophenone hydrazones gave similar products.Cyclization of 2-methoxy-6- (p-nitrobenzyloxy)acetophenone hydrazone gave 2-(p-nitrophenyl)-3-methyl-4-methoxy benzo- furan and 3-methyl-4-methoxy indazole while 2-methoxy-6-(m-nitrobenzyloxy)acetophenone hydrazone gave 3-methyl-4-methoxy indazole,3-methyl-4-methoxy-7-(m-nitrophenyl)indazole and 3-methyl-4-(m-nitrobenzyloxy)indazole.
文摘Silica gel-supported polyphosphoric acid （PPA-SiO2） was found to be an efficient catalyst for the one-pot four-component Hantzsch condensation reaction of aryl aldehydes, dimedone, ethyl acetoacetate and ammonium acetate to afford the corresponding polyhydroquinoline derivatives in high yields. The main advantages of the present approach are short reaction times, clean reaction profiles, simple experimental and workup procedures.
文摘In this study,6-chloro-4-hydroxy-2-quinolone and 6-flouro-4-hydroxy-2-quinolone were synthesized from corresponding dianilides.These compounds were coupled with some diazotized aromatic amines to give the corresponding azo disperse dyes.The structures of the quinolone derivatives and new azo dyes were confirmed by UV-vis,FT-IR,;H NMR and elemental analysis.
文摘A facile synthesis of a series of new quinoline-8-carbaldehyde compounds, namely 8-formyl-2- （phenoxymethyl）quinoline-3-carboxylic acids （4a--4h） and 13-oxo-6,13-dihydro[1]benzoxepino[3,4-b]quinoline- 8-carbaldehyde （5a--5g） is described, involving the one-pot synthesis reaction of ethyl 2-（chloromethyl）-8- formylquinoline-3-carboxylate （3） with substituted phenols followed by the intramolecular cyclization reaction via the treatment with polyphosphoric acid （PPA）. Quinoline-8-carbaldehydes 4a--4h and 5a--5g are novel and their structures were supported by IR, IH NMR, 13C NMR, MS and elemental analysis.
