A formal[3+3]annulation of 3-aminopyrazoles with cinnamaldehydes or cinnamyl alcohols mediated by NH_(4)SCN has been developed.This protocol provides a practical route to construct 5-arylated pyrazolo[1,5-a]pyrimidine...A formal[3+3]annulation of 3-aminopyrazoles with cinnamaldehydes or cinnamyl alcohols mediated by NH_(4)SCN has been developed.This protocol provides a practical route to construct 5-arylated pyrazolo[1,5-a]pyrimidines with high functional group tolerance.The use of NH_(4)SCN as the cyanide anion surrogate allows the transient generation of cyanohydrin,which shifts the reactive center within cinnamaldehydes from formyl group to alkene group to realize an opposite regiocontrol comparing with previous reports.展开更多
Condensation of D-glucose, o-phenylenediamine and N,N-benzylphenylhydrazine hydrochloride (NNBPHH) in a one-pot reaction, or condensation of 2-(D-arabino-tetritol-1-yl) quinoxaline and NNBPHH, gave 3-(D-erythro-glycer...Condensation of D-glucose, o-phenylenediamine and N,N-benzylphenylhydrazine hydrochloride (NNBPHH) in a one-pot reaction, or condensation of 2-(D-arabino-tetritol-1-yl) quinoxaline and NNBPHH, gave 3-(D-erythro-glycerol-1- yl)-1-phenyl-1H-pyrazolo[3,4-b]quinoxaline. The structure of the latter was determined by 1H NMR spectroscopy and by synthesis using phenylhydrazine hydrochloride instead of NNBPHH. Condensation of D-glucose and 4,5-dichloro-o-phenylenediamine gave 6,7-dichloro-2-(D-arabino-tetritol-1-yl)quinoxaline, which upon condensation with NNBPHH gave the corresponding 6,7-dichloro-3-(D-erythro-glycerol-1-yl)-1-phenyl-1H-pyrazolo[3,4-b]quinoxaline. The structure and mechanism of formation of these compounds are discussed.展开更多
Reaction of 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile) (1) with methyl iodide afforded the 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-(methylthio)nicotinonitrile) (2). Th...Reaction of 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile) (1) with methyl iodide afforded the 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-(methylthio)nicotinonitrile) (2). The reaction of 2 with hydrazine hydrate followed by diazotization reaction af-forded the 1,1’-(1,4-phenylenebis(3-amino-6-methyl-1H-pyrazolo[3,4-b]pyridine-4,5-diyl))bis(e-than-1-one) (3) and 1,1’-(1,4-phenylenebis(3-(chlorodiazenyl)-6-methyl-1H-pyrazolo[3,4-b]-pyridine-4,5-diyl))bis(ethan-1-one) (4) respectively. On the other hand, reaction of 4 with malononitrile, 2-cyanoethanethioamide, ethyl acetoacetate, acetyl acetone, ethyl benzoylacetate, diethylmalonate, ethyl cyanoacetate and phenacylbromide aiming to build up pyrazolotriazine or pyrazole ring on the ring system of 4. Structures of all newly synthesized heterocyclic compounds in the present study were confirmed by considering the data of IR, 1H NMR, mass spectra as well as that of elemental analyses.展开更多
A facile microwave-assisted procedure for synthesis of novel fluorinated pyrazolo[3,4-d]pyrimidine derivatives containing 1,3,4-thiadiazole is described. This protocol presented such advantages as short reaction time,...A facile microwave-assisted procedure for synthesis of novel fluorinated pyrazolo[3,4-d]pyrimidine derivatives containing 1,3,4-thiadiazole is described. This protocol presented such advantages as short reaction time, high yields, simple purification and environmentally benign procedures. Their antitumor activities were evaluated against HL-60 by an MTT assay. The preliminary results indicated that some title compounds exhibit more potent antitumor inhibitory activity than doxorubicin （DOX）.展开更多
An efficient and novel procedure for the preparation of pyrazolo[3,4-b]pyridine derivatives through multi-component reaction of aldehyde, 5-amino-3-methyl-1-phenylpyrazole and malononitrile or cyanoacetate in [bmim][B...An efficient and novel procedure for the preparation of pyrazolo[3,4-b]pyridine derivatives through multi-component reaction of aldehyde, 5-amino-3-methyl-1-phenylpyrazole and malononitrile or cyanoacetate in [bmim][BF4] is described in this paper. Advantages of the method presented here include mild conditions, high yields together with a green nature and ease of recovery and reuse of the reaction medium.展开更多
A one-pot, three-component condensation reaction of an aldehyde, benzoyl acetonitrile （3-oxo-3-phenylpropane nitrile） and 6- amino-1,3-dimethylpyrimidine-2,4（1H,3H）-dione or 3-methyl-l-phenyl-lH-pyrazol-5-amine in...A one-pot, three-component condensation reaction of an aldehyde, benzoyl acetonitrile （3-oxo-3-phenylpropane nitrile） and 6- amino-1,3-dimethylpyrimidine-2,4（1H,3H）-dione or 3-methyl-l-phenyl-lH-pyrazol-5-amine in water to give fused pyrido[2,3- d]pyrimidines and pyrazolo[3,4-b]pyridines in high yields without any catalyst, is described.展开更多
The novel title compound 1-（4-methoxybenzylidene）-2-（1-phenyl-6-trifluoromethyl- 1H-pyrazolo[3,4-d]pyrimidin-4-yl）hydrazine monohydrate （C20HisF3N60-H20, Mr = 430.40） has been synthesized by a four-step procedur...The novel title compound 1-（4-methoxybenzylidene）-2-（1-phenyl-6-trifluoromethyl- 1H-pyrazolo[3,4-d]pyrimidin-4-yl）hydrazine monohydrate （C20HisF3N60-H20, Mr = 430.40） has been synthesized by a four-step procedure including the cyclization, chlorination, hydrazinolysis and condensation reaction, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to orthorhombic, space groupPbca with a = 8.3779（13）, b = 17.607（3）, c = 26.774（4） A, V= 3949.2（11） A3, Z=8, Dc = 1.448 g/cm3, μ = 0.117 mm-l, F（000） = 1776, the final R = 0.0553 and wR = 0.1516 for 2354 observed reflections with 1 〉 2σ（/）. X-ray diffraction analysis reveals that the title compound is almost coplanar except for the trifluoromethyl and phenyl moieties. In the crystal packing, the molecules are linked by intermolecular O（lW）-H（1WA）-＂N（2）, O（1W）-H（1WA）.--N（4） and N（5）-H（5A）...O（lW） hydrogen bonds via water molecules and stacked through π-π stacking interactions. The preliminary bioassay suggested that the title compound exhibits relatively good antitumor activity against HepG2 and BCG-823.展开更多
The new regioisomer 7-methyl-pyrazolo[4,5-e][1,2,4]thiadiazine nucleus (5) was synthesized, and its novel mono-N2- or N4-substituted pyrazolo[4,5-e][1,2,4]thiadiazines (6, 7) were regioselectively prepared by deproton...The new regioisomer 7-methyl-pyrazolo[4,5-e][1,2,4]thiadiazine nucleus (5) was synthesized, and its novel mono-N2- or N4-substituted pyrazolo[4,5-e][1,2,4]thiadiazines (6, 7) were regioselectively prepared by deprotonation of N2 or/and N4 atoms with different molar ratio of NaH and alkyl halides. Anti-HIV-1 screening tests showed some compounds to be potent as HIV-1 non-nucleoside reverse transcriptase inhibitors (HIV-1 NNRTIs).展开更多
New series of pyrazolo[1,5-α]pyrimidine derivatives 7a-i,11a-c and Schiff bases 13a-c were synthesized and screened for their in vitro antitumor activity against three human carcinoma cell lines,namely colorectal car...New series of pyrazolo[1,5-α]pyrimidine derivatives 7a-i,11a-c and Schiff bases 13a-c were synthesized and screened for their in vitro antitumor activity against three human carcinoma cell lines,namely colorectal carcinoma（HCT116）,prostate adenocarcinoma（PC-3） and liver carcinoma（HepG-2） using MTT cytotoxicity assay at 100 μg/mL.Some of the tested compounds displayed good anticancer activities against HCT-116 and PC-3 cells.Whereas,compounds 7d and 11 a showed better antitumor activity than the rest of the compounds against both cell lines.A structure-activity relationship（SAR） has been discussed and structures of the newly synthesized compounds were confirmed by different spectral data（MS,IR,^1H NMR and ^13C NMR） and elemental analysis.展开更多
An efficient ultrasound-assisted preparation of a series of novel 4-aryl-3-methyl-4,5-dihydro-l//-pyrazolo[34-b]pyridin-6（7H）ones via the reaction of 5-amino-3-methyl-1H-pyrazole,Meldrum＇s acid and various arylalde...An efficient ultrasound-assisted preparation of a series of novel 4-aryl-3-methyl-4,5-dihydro-l//-pyrazolo[34-b]pyridin-6（7H）ones via the reaction of 5-amino-3-methyl-1H-pyrazole,Meldrum＇s acid and various arylaldehydes using one-pot three-component approach is described.This rapid method produced the products in short reaction times（3-4 min） and excellent yields（87-95%）.展开更多
A series of novel pyrazolo [ 4,3-d ] pyrimidin-7-ones was designed and synthesized in order to find new potent phosphodiesterase 5 inhibitors（PDE5）. The structures of all the compounds were confirmed by IR, ^1H NMR ...A series of novel pyrazolo [ 4,3-d ] pyrimidin-7-ones was designed and synthesized in order to find new potent phosphodiesterase 5 inhibitors（PDE5）. The structures of all the compounds were confirmed by IR, ^1H NMR and MS; their in vitro vasodilatory activities were tested on isolated rabbit aortic spiral strips. Among them, compound X3 displays a significant vasodilatory activity, which is more potent than verapamil.展开更多
Novel heteropolycyclic nitrogen systems bearing fluorine substituted pyrazolo[3,4-d] pyrimidine moiety have been synthesis by the interaction between N’-heteroaryl guanidine 4 with polyfunctional π-acceptors in diff...Novel heteropolycyclic nitrogen systems bearing fluorine substituted pyrazolo[3,4-d] pyrimidine moiety have been synthesis by the interaction between N’-heteroaryl guanidine 4 with polyfunctional π-acceptors in different media and condition. The structures of the synthesis compounds were established by spectroscopic analysis and evaluated as antifungal probes in various concentration.展开更多
Ethyl 7-aryl-2-benzyhhiopyrazolo [ 1,5-a ] pyrimidine-3-carboxylates （3a-3f） were conveniently synthesized through the reactions of enaminones with 5-amino-3-benzyhhio4-ethoxycarbonyl-1 H-pyrazole in good yields and...Ethyl 7-aryl-2-benzyhhiopyrazolo [ 1,5-a ] pyrimidine-3-carboxylates （3a-3f） were conveniently synthesized through the reactions of enaminones with 5-amino-3-benzyhhio4-ethoxycarbonyl-1 H-pyrazole in good yields and high regioselectivity. The structures of the new compounds were fully characterized by spectroscopic measurmehts, elemental analysis and X-ray diffraction analysis. A plausible reaction mechanism for the formation of the title compounds was also presented.展开更多
On the basis of the Zaleplon structure, novel pyrazolo[l,5-a]pyrimidines were designed and prepared for studies on their hypnotic activity. This paper reported the synthesis of twelve new 5-methyl-7-substituted-pyrazo...On the basis of the Zaleplon structure, novel pyrazolo[l,5-a]pyrimidines were designed and prepared for studies on their hypnotic activity. This paper reported the synthesis of twelve new 5-methyl-7-substituted-pyrazolo[1,5-a]pyrimidine-3-carbonitrile derivatives by using simple starting materials such as propane dinitrile and triethyl orthoformate. The structures of the derived target compounds were confirmed by their IR and 1H-NMR spectroscopic data. The preliminary pharmacological evaluations indicated that some compounds showed hypnotic activity, while derivative 1c was the most polent one.展开更多
The crystal structure of 2-methylthio-3-cyano-7-（4-methoxyphenyl）-pyrazolo[1,5- a]-pyrimidine （C15H12N4OS, Mr = 296.35） has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to mono...The crystal structure of 2-methylthio-3-cyano-7-（4-methoxyphenyl）-pyrazolo[1,5- a]-pyrimidine （C15H12N4OS, Mr = 296.35） has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to monoclinic, space group P21/c with a = 9.200（3）, b = 15.570（5）, c = 11.125（4） A,β= 114.273（6）°, V= 1452.7（8） A^3, Z= 4, De= 1.355 g/cm^3, μ= 0.227 mm^-1, F（000） = 616, R = 0.0499 and wR = 0.0949 for 2947 unique reflections with 1633 observed ones （I 〉 2σ（I））. The results show that all ring atoms in the pyrazolopyrimidine moiety are almost coplanar with a strong tensile force, which might be an important active site. The preliminary biological test shows that the title compound has moderate herbicidal activities.展开更多
An unexpected multi-component reaction of cyanothioacetarnide with aldehyde and aminopyrazole under MWI was reported. Through this reaction, a series of pyrazolo[3,4-b]-pyridine derivatives was prepared in high yields...An unexpected multi-component reaction of cyanothioacetarnide with aldehyde and aminopyrazole under MWI was reported. Through this reaction, a series of pyrazolo[3,4-b]-pyridine derivatives was prepared in high yields via simple operational procedure.展开更多
The title compound 1,2-bis(1-phenyl-3-methylthio-4-iminopyrazolo[3,4-d] pyrimidin-5-yl)ethane (C26H24N10S2, Mr = 540.67) was obtained by the reaction of (1-phenyl-4- cyano)pyrazol-5-yliminomethyl ethyl ether with ethy...The title compound 1,2-bis(1-phenyl-3-methylthio-4-iminopyrazolo[3,4-d] pyrimidin-5-yl)ethane (C26H24N10S2, Mr = 540.67) was obtained by the reaction of (1-phenyl-4- cyano)pyrazol-5-yliminomethyl ethyl ether with ethyldiamine. The crystal is monoclinic, space group P21/c with a = 10.460(2), b = 8.004(2), c =15.434(3) ? b = 90.803(3)? V = 1292.1(4) 3, Z = 2, Dc = 1.390 g/cm3, F(000) = 564, m(MoKa) = 0.24 mm-1, R = 0.0560 and wR = 0.1344 for 2286 observed reflections (I > 2s (I)). In this compound the dihedral angle between the plane defined by C(2), N(1), N(2), C(3), C(6), N(3), C(4), N(4), C(5) and N(5) atoms and the phenyl ring is 34.78? The six-membered ring consisted of C(3), N(3), C(4), N(4), C(5) and C(6) atoms forms a p67 configuration in which the N(4) atom is sp2 hybrid. There exist weak hydrogen bonds between S(1) and N(5) atoms (NHS, 3.430 ?.展开更多
Twelve novel pyrazolo [4,3-d] pyrimidin-7-ones were synthesized and their structures were confirmed by IR, 1H NMR and MS. Their in vitro bronchodilatory activities were tested in guinea-pigs. The pharmacological res...Twelve novel pyrazolo [4,3-d] pyrimidin-7-ones were synthesized and their structures were confirmed by IR, 1H NMR and MS. Their in vitro bronchodilatory activities were tested in guinea-pigs. The pharmacological results show that compound 11c has more potent activity than aminophylline.展开更多
A series of pyrazolo[3,4-d]pyrimidin-4-one derivatives were synthesized and tested for vasodilatory activities. All of them were new compounds and their structures were confirmed by IR, 1H NMR, MS and elemental analy...A series of pyrazolo[3,4-d]pyrimidin-4-one derivatives were synthesized and tested for vasodilatory activities. All of them were new compounds and their structures were confirmed by IR, 1H NMR, MS and elemental analysis.展开更多
The crystal structure of ethyl 2-methylthio-7-phenylpyrazolo[1,5-a]pyrimidine-3- carboxylate (C16H15N3O2S, Mr = 313.37) has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to monocl...The crystal structure of ethyl 2-methylthio-7-phenylpyrazolo[1,5-a]pyrimidine-3- carboxylate (C16H15N3O2S, Mr = 313.37) has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to monoclinic, space group P21/n with a = 19.361(7), b = 7.595(3), c = 20.910(8) ?, β = 94.925(6)°, V = 3064(2) ?3, Z = 8, Dc = 1.359 g/cm3, μ = 0.222 mm-1, F(000) = 1312, R = 0.0546 and wR = 0.1082 for 5374 unique reflections with 3419 observed ones (I > 2σ(I)). The results show that all ring atoms in the pyrazolopyrimidine moiety are coplanar with strong tensile force. The structure analysis indicates that the single crystal contains strong nonclassical hydrogen bonds.展开更多
文摘A formal[3+3]annulation of 3-aminopyrazoles with cinnamaldehydes or cinnamyl alcohols mediated by NH_(4)SCN has been developed.This protocol provides a practical route to construct 5-arylated pyrazolo[1,5-a]pyrimidines with high functional group tolerance.The use of NH_(4)SCN as the cyanide anion surrogate allows the transient generation of cyanohydrin,which shifts the reactive center within cinnamaldehydes from formyl group to alkene group to realize an opposite regiocontrol comparing with previous reports.
文摘Condensation of D-glucose, o-phenylenediamine and N,N-benzylphenylhydrazine hydrochloride (NNBPHH) in a one-pot reaction, or condensation of 2-(D-arabino-tetritol-1-yl) quinoxaline and NNBPHH, gave 3-(D-erythro-glycerol-1- yl)-1-phenyl-1H-pyrazolo[3,4-b]quinoxaline. The structure of the latter was determined by 1H NMR spectroscopy and by synthesis using phenylhydrazine hydrochloride instead of NNBPHH. Condensation of D-glucose and 4,5-dichloro-o-phenylenediamine gave 6,7-dichloro-2-(D-arabino-tetritol-1-yl)quinoxaline, which upon condensation with NNBPHH gave the corresponding 6,7-dichloro-3-(D-erythro-glycerol-1-yl)-1-phenyl-1H-pyrazolo[3,4-b]quinoxaline. The structure and mechanism of formation of these compounds are discussed.
文摘Reaction of 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile) (1) with methyl iodide afforded the 4,4’-(1,4-phenylene)bis(5-acetyl-6-methyl-2-(methylthio)nicotinonitrile) (2). The reaction of 2 with hydrazine hydrate followed by diazotization reaction af-forded the 1,1’-(1,4-phenylenebis(3-amino-6-methyl-1H-pyrazolo[3,4-b]pyridine-4,5-diyl))bis(e-than-1-one) (3) and 1,1’-(1,4-phenylenebis(3-(chlorodiazenyl)-6-methyl-1H-pyrazolo[3,4-b]-pyridine-4,5-diyl))bis(ethan-1-one) (4) respectively. On the other hand, reaction of 4 with malononitrile, 2-cyanoethanethioamide, ethyl acetoacetate, acetyl acetone, ethyl benzoylacetate, diethylmalonate, ethyl cyanoacetate and phenacylbromide aiming to build up pyrazolotriazine or pyrazole ring on the ring system of 4. Structures of all newly synthesized heterocyclic compounds in the present study were confirmed by considering the data of IR, 1H NMR, mass spectra as well as that of elemental analyses.
基金the National Nature Science Foundation of Hubei Province(No.2008CDB016)the Scientific Research Fund of Hubei Provincial Education Department(No.D20111904)
文摘A facile microwave-assisted procedure for synthesis of novel fluorinated pyrazolo[3,4-d]pyrimidine derivatives containing 1,3,4-thiadiazole is described. This protocol presented such advantages as short reaction time, high yields, simple purification and environmentally benign procedures. Their antitumor activities were evaluated against HL-60 by an MTT assay. The preliminary results indicated that some title compounds exhibit more potent antitumor inhibitory activity than doxorubicin （DOX）.
基金the National Natural Science Foundation of China(No.20573034).
文摘An efficient and novel procedure for the preparation of pyrazolo[3,4-b]pyridine derivatives through multi-component reaction of aldehyde, 5-amino-3-methyl-1-phenylpyrazole and malononitrile or cyanoacetate in [bmim][BF4] is described in this paper. Advantages of the method presented here include mild conditions, high yields together with a green nature and ease of recovery and reuse of the reaction medium.
基金the financial support of the Research Council of the University of Isfahan
文摘A one-pot, three-component condensation reaction of an aldehyde, benzoyl acetonitrile （3-oxo-3-phenylpropane nitrile） and 6- amino-1,3-dimethylpyrimidine-2,4（1H,3H）-dione or 3-methyl-l-phenyl-lH-pyrazol-5-amine in water to give fused pyrido[2,3- d]pyrimidines and pyrazolo[3,4-b]pyridines in high yields without any catalyst, is described.
基金Supported by the National Natural Science Foundation of China(No.21262012)the Open Fund of Key Laboratory of Biologic Resources Protection and Utilization of Hubei Province(No.PKLHB1314)+1 种基金the Project for Cultivating Excellent Postgraduate's Dissertation of Hubei Minzu University(PY201402)the First-class Discipline of Forestry in Hubei Minzu University
文摘The novel title compound 1-（4-methoxybenzylidene）-2-（1-phenyl-6-trifluoromethyl- 1H-pyrazolo[3,4-d]pyrimidin-4-yl）hydrazine monohydrate （C20HisF3N60-H20, Mr = 430.40） has been synthesized by a four-step procedure including the cyclization, chlorination, hydrazinolysis and condensation reaction, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to orthorhombic, space groupPbca with a = 8.3779（13）, b = 17.607（3）, c = 26.774（4） A, V= 3949.2（11） A3, Z=8, Dc = 1.448 g/cm3, μ = 0.117 mm-l, F（000） = 1776, the final R = 0.0553 and wR = 0.1516 for 2354 observed reflections with 1 〉 2σ（/）. X-ray diffraction analysis reveals that the title compound is almost coplanar except for the trifluoromethyl and phenyl moieties. In the crystal packing, the molecules are linked by intermolecular O（lW）-H（1WA）-＂N（2）, O（1W）-H（1WA）.--N（4） and N（5）-H（5A）...O（lW） hydrogen bonds via water molecules and stacked through π-π stacking interactions. The preliminary bioassay suggested that the title compound exhibits relatively good antitumor activity against HepG2 and BCG-823.
文摘The new regioisomer 7-methyl-pyrazolo[4,5-e][1,2,4]thiadiazine nucleus (5) was synthesized, and its novel mono-N2- or N4-substituted pyrazolo[4,5-e][1,2,4]thiadiazines (6, 7) were regioselectively prepared by deprotonation of N2 or/and N4 atoms with different molar ratio of NaH and alkyl halides. Anti-HIV-1 screening tests showed some compounds to be potent as HIV-1 non-nucleoside reverse transcriptase inhibitors (HIV-1 NNRTIs).
文摘New series of pyrazolo[1,5-α]pyrimidine derivatives 7a-i,11a-c and Schiff bases 13a-c were synthesized and screened for their in vitro antitumor activity against three human carcinoma cell lines,namely colorectal carcinoma（HCT116）,prostate adenocarcinoma（PC-3） and liver carcinoma（HepG-2） using MTT cytotoxicity assay at 100 μg/mL.Some of the tested compounds displayed good anticancer activities against HCT-116 and PC-3 cells.Whereas,compounds 7d and 11 a showed better antitumor activity than the rest of the compounds against both cell lines.A structure-activity relationship（SAR） has been discussed and structures of the newly synthesized compounds were confirmed by different spectral data（MS,IR,^1H NMR and ^13C NMR） and elemental analysis.
基金Financial support from the Research Council of University of Guilan is sincerely acknowledged
文摘An efficient ultrasound-assisted preparation of a series of novel 4-aryl-3-methyl-4,5-dihydro-l//-pyrazolo[34-b]pyridin-6（7H）ones via the reaction of 5-amino-3-methyl-1H-pyrazole,Meldrum＇s acid and various arylaldehydes using one-pot three-component approach is described.This rapid method produced the products in short reaction times（3-4 min） and excellent yields（87-95%）.
基金Supported by the Natural Science Foundation of Liaoning Province(No. 20032043)
文摘A series of novel pyrazolo [ 4,3-d ] pyrimidin-7-ones was designed and synthesized in order to find new potent phosphodiesterase 5 inhibitors（PDE5）. The structures of all the compounds were confirmed by IR, ^1H NMR and MS; their in vitro vasodilatory activities were tested on isolated rabbit aortic spiral strips. Among them, compound X3 displays a significant vasodilatory activity, which is more potent than verapamil.
文摘Novel heteropolycyclic nitrogen systems bearing fluorine substituted pyrazolo[3,4-d] pyrimidine moiety have been synthesis by the interaction between N’-heteroaryl guanidine 4 with polyfunctional π-acceptors in different media and condition. The structures of the synthesis compounds were established by spectroscopic analysis and evaluated as antifungal probes in various concentration.
文摘Ethyl 7-aryl-2-benzyhhiopyrazolo [ 1,5-a ] pyrimidine-3-carboxylates （3a-3f） were conveniently synthesized through the reactions of enaminones with 5-amino-3-benzyhhio4-ethoxycarbonyl-1 H-pyrazole in good yields and high regioselectivity. The structures of the new compounds were fully characterized by spectroscopic measurmehts, elemental analysis and X-ray diffraction analysis. A plausible reaction mechanism for the formation of the title compounds was also presented.
文摘On the basis of the Zaleplon structure, novel pyrazolo[l,5-a]pyrimidines were designed and prepared for studies on their hypnotic activity. This paper reported the synthesis of twelve new 5-methyl-7-substituted-pyrazolo[1,5-a]pyrimidine-3-carbonitrile derivatives by using simple starting materials such as propane dinitrile and triethyl orthoformate. The structures of the derived target compounds were confirmed by their IR and 1H-NMR spectroscopic data. The preliminary pharmacological evaluations indicated that some compounds showed hypnotic activity, while derivative 1c was the most polent one.
文摘The crystal structure of 2-methylthio-3-cyano-7-（4-methoxyphenyl）-pyrazolo[1,5- a]-pyrimidine （C15H12N4OS, Mr = 296.35） has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to monoclinic, space group P21/c with a = 9.200（3）, b = 15.570（5）, c = 11.125（4） A,β= 114.273（6）°, V= 1452.7（8） A^3, Z= 4, De= 1.355 g/cm^3, μ= 0.227 mm^-1, F（000） = 616, R = 0.0499 and wR = 0.0949 for 2947 unique reflections with 1633 observed ones （I 〉 2σ（I））. The results show that all ring atoms in the pyrazolopyrimidine moiety are almost coplanar with a strong tensile force, which might be an important active site. The preliminary biological test shows that the title compound has moderate herbicidal activities.
基金We are grateful for the financial support from the National Natural Science Foundation of China （No. 20772025）
文摘An unexpected multi-component reaction of cyanothioacetarnide with aldehyde and aminopyrazole under MWI was reported. Through this reaction, a series of pyrazolo[3,4-b]-pyridine derivatives was prepared in high yields via simple operational procedure.
基金The project was supported by the National Natural Science Foundation of China (29832025)
文摘The title compound 1,2-bis(1-phenyl-3-methylthio-4-iminopyrazolo[3,4-d] pyrimidin-5-yl)ethane (C26H24N10S2, Mr = 540.67) was obtained by the reaction of (1-phenyl-4- cyano)pyrazol-5-yliminomethyl ethyl ether with ethyldiamine. The crystal is monoclinic, space group P21/c with a = 10.460(2), b = 8.004(2), c =15.434(3) ? b = 90.803(3)? V = 1292.1(4) 3, Z = 2, Dc = 1.390 g/cm3, F(000) = 564, m(MoKa) = 0.24 mm-1, R = 0.0560 and wR = 0.1344 for 2286 observed reflections (I > 2s (I)). In this compound the dihedral angle between the plane defined by C(2), N(1), N(2), C(3), C(6), N(3), C(4), N(4), C(5) and N(5) atoms and the phenyl ring is 34.78? The six-membered ring consisted of C(3), N(3), C(4), N(4), C(5) and C(6) atoms forms a p67 configuration in which the N(4) atom is sp2 hybrid. There exist weak hydrogen bonds between S(1) and N(5) atoms (NHS, 3.430 ?.
文摘Twelve novel pyrazolo [4,3-d] pyrimidin-7-ones were synthesized and their structures were confirmed by IR, 1H NMR and MS. Their in vitro bronchodilatory activities were tested in guinea-pigs. The pharmacological results show that compound 11c has more potent activity than aminophylline.
文摘A series of pyrazolo[3,4-d]pyrimidin-4-one derivatives were synthesized and tested for vasodilatory activities. All of them were new compounds and their structures were confirmed by IR, 1H NMR, MS and elemental analysis.
基金The project was supported by the Natural Science Foundation of Shandong Province (No. Y2003B01) NNSFC (No. 20172031)
文摘The crystal structure of ethyl 2-methylthio-7-phenylpyrazolo[1,5-a]pyrimidine-3- carboxylate (C16H15N3O2S, Mr = 313.37) has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to monoclinic, space group P21/n with a = 19.361(7), b = 7.595(3), c = 20.910(8) ?, β = 94.925(6)°, V = 3064(2) ?3, Z = 8, Dc = 1.359 g/cm3, μ = 0.222 mm-1, F(000) = 1312, R = 0.0546 and wR = 0.1082 for 5374 unique reflections with 3419 observed ones (I > 2σ(I)). The results show that all ring atoms in the pyrazolopyrimidine moiety are coplanar with strong tensile force. The structure analysis indicates that the single crystal contains strong nonclassical hydrogen bonds.
