5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines
- Ranjana Aggarwal and
- Suresh Kumar
Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15
Graphical Abstract
Figure 1: Selected examples of drugs with fused pyrazole rings.
Figure 2: Typical structures of some fused pyrazoloazines from 5-aminopyrazoles.
Scheme 1: Regiospecific synthesis of 4 and 6-trifluoromethyl-1H-pyrazolo[3,4-b]pyridines.
Scheme 2: Synthesis of pyrazolo[3,4-b]pyridine-6-carboxylates.
Scheme 3: Synthesis of 1,4,6-triaryl-1H-pyrazolo[3,4-b]pyridines with ionic liquid .
Scheme 4: Synthesis of coumarin-based isomeric tetracyclic pyrazolo[3,4-b]pyridines.
Scheme 5: Synthesis of 6-substituted pyrazolo[3,4-b]pyridines under Heck conditions.
Scheme 6: Microwave-assisted palladium-catalyzed synthesis of pyrazolo[3,4-b]pyridines.
Scheme 7: Acid-catalyzed synthesis of pyrazolo[3,4-b]pyridines via enaminones.
Scheme 8: Synthesis of pyrazolo[3,4-b]pyridines via aza-Diels–Alder reaction.
Scheme 9: Synthesis of macrocyclane fused pyrazolo[3,4-b]pyridine derivatives.
Scheme 10: Three-component synthesis of 4,7-dihydro-1H-pyrazolo[3,4-b]pyridine derivatives.
Scheme 11: Ultrasonicated synthesis of spiro[indoline-3,4'-pyrazolo[3,4-b]pyridine]-2,6'(1'H)-diones.
Scheme 12: Synthesis of spiro[indoline-3,4'-pyrazolo[3,4-b]pyridine] derivatives under conventional heating co...
Scheme 13: Nanoparticle-catalyzed synthesis of pyrazolo[3,4-b]pyridine-spiroindolinones.
Scheme 14: Microwave-assisted multicomponent synthesis of spiropyrazolo[3,4-b]pyridines.
Scheme 15: Unexpected synthesis of naphthoic acid-substituted pyrazolo[3,4-b]pyridines.
Scheme 16: Multicomponent synthesis of variously substituted pyrazolo[3,4-b]pyridine derivatives.
Scheme 17: Three-component synthesis of 4,7-dihydropyrazolo[3,4-b]pyridines and pyrazolo[3,4-b]pyridines.
Scheme 18: Synthesis of pyrazolo[3,4-b]pyridine-5-spirocycloalkanediones.
Scheme 19: Ultrasound-mediated three-component synthesis of pyrazolo[3,4-b]pyridines.
Scheme 20: Multicomponent synthesis of 4-aryl-3-methyl-1-phenyl-4,6,8,9-tetrahydropyrazolo [3,4-b]thiopyrano[4...
Scheme 21: Synthesis of 2,3-dihydrochromeno[4,3-d]pyrazolo[3,4-b]pyridine-1,6-diones.
Scheme 22: FeCl3-catalyzed synthesis of o-hydroxyphenylpyrazolo[3,4-b]pyridine derivatives.
Scheme 23: Ionic liquid-mediated synthesis of pyrazolo[3,4-b]pyridines.
Scheme 24: Microwave-assisted synthesis of pyrazolo[3,4-b]pyridines.
Scheme 25: Multicomponent synthesis of pyrazolo[3,4-b]pyridine-5-carbonitriles.
Scheme 26: Unusual domino synthesis of 4,7-dihydropyrazolo[3,4-b]pyridine-5-nitriles.
Scheme 27: Synthesis of 4,5,6,7-tetrahydro-4H-pyrazolo[3,4-b]pyridines under conventional heating and ultrasou...
Scheme 28: L-Proline-catalyzed synthesis of of pyrazolo[3,4-b]pyridine.
Scheme 29: Microwave-assisted synthesis of 5-aminoarylpyrazolo[3,4-b]pyridines.
Scheme 30: Microwave-assisted multi-component synthesis of pyrazolo[3,4-e]indolizines.
Scheme 31: Synthesis of fluoropropynyl and fluoroalkyl substituted pyrazolo[1,5-a]pyrimidine.
Scheme 32: Acid-catalyzed synthesis of pyrazolo[1,5-a]pyrimidine derivatives.
Scheme 33: Chemoselective and regiospecific synthesis of 2-(3-methylpyrazol-1’-yl)-5-methylpyrazolo[1,5-a]pyri...
Scheme 34: Regioselective synthesis of 7-trifluoromethylpyrazolo[1,5-a]pyrimidines.
Scheme 35: Microwave-assisted synthesis of 7-trifluoromethylpyrazolo[1,5-a]pyrimidine carboxylates.
Scheme 36: Microwave and ultrasound-assisted synthesis of 7-trifluoromethylpyrazolo[1,5-a]pyrimidines.
Scheme 37: Base-catalyzed unprecedented synthesis of pyrazolo[1,5-a]pyrimidines via C–C bond cleavage.
Scheme 38: Synthesis of aminobenzothiazole/piperazine linked pyrazolo[1,5-a]pyrimidines.
Scheme 39: Synthesis of aminoalkylpyrazolo[1,5-a]pyrimidine-7-amines.
Scheme 40: Synthesis of pyrazolo[1,5-a]pyrimidines from condensation of 5-aminopyrazole 126 and ethyl acetoace...
Scheme 41: Synthesis of 7-aminopyrazolo[1,5-a]pyrimidines.
Scheme 42: Unexpected synthesis of 7-aminopyrazolo[1,5-a]pyrimidines under solvent free and solvent-mediated c...
Scheme 43: Synthesis of N-(4-aminophenyl)-7-aryloxypyrazolo[1,5-a]pyrimidin-5-amines.
Scheme 44: Base-catalyzed synthesis of 5,7-diarylpyrazolo[1,5-a]pyrimidines.
Scheme 45: Synthesis of 6,7-dihydropyrazolo[1,5-a]pyrimidines in PEG-400.
Scheme 46: Synthesis of 7-heteroarylpyrazolo[1,5-a]pyrimidine-3-carboxamides.
Scheme 47: Synthesis of 7-heteroarylpyrazolo[1,5-a]pyrimidine derivatives under conventional heating and micro...
Scheme 48: Synthesis of N-aroylpyrazolo[1,5-a]pyrimidine-5-amines.
Scheme 49: Regioselective synthesis of ethyl pyrazolo[1,5-a]pyrimidine-7-carboxylate.
Scheme 50: Sodium methoxide-catalyzed synthesis of 3-cyano-6,7-diarylpyrazolo[1,5-a]pyrimidines.
Scheme 51: Synthesis of various pyrazolo[3,4-d]pyrimidine derivatives.
Scheme 52: Synthesis of hydrazinopyrazolo[3,4-d]pyrimidine derivatives.
Scheme 53: Synthesis of N-arylidinepyrazolo[3,4-d]pyrimidin-5-amines.
Scheme 54: Synthesis of pyrazolo[3,4-d]pyrimidinyl-4-amines.
Scheme 55: Iodine-catalyzed synthesis of pyrazolo[3,4-d]pyrimidinones.
Scheme 56: Synthesis of ethyl 6-amino-2H-pyrazolo[3,4-d]pyrimidine-4-carboxylate.
Scheme 57: Synthesis of 4-substituted-(3,6-dihydropyran-4-yl)-1H-pyrazolo[3,4-d]pyrimidines.
Scheme 58: Synthesis of 1-(2,4-dichlorophenyl)pyrazolo[3,4-d]pyrimidin-4-yl carboxamides.
Scheme 59: Synthesis of 5-(1,3,4-thidiazol-2-yl)pyrazolo[3,4-d]pyrimidine.
Scheme 60: One pot POCl3-catalyzed synthesis of 1-arylpyrazolo[3,4-d]pyrimidin-4-ones.
Scheme 61: Synthesis of 4-amino-N1,C3-dialkylpyrazolo[3,4-d]pyrimidines under Suzuki conditions.
Scheme 62: Microwave-assisted synthesis of pyrazolo[3,4-b]pyrazines.
Scheme 63: Synthesis and derivatization of pyrazolo[3,4-b]pyrazine-5-carbonitriles.
Scheme 64: Synthesis of 2-thioxo-pyrazolo[1,5-a][1,3,5]triazin-4-ones.
Scheme 65: Synthesis of 2,3-dihydropyrazolo[1,5-a][1,3,5]triazin-4(1H)-one.
Scheme 66: Synthesis of pyrazolo[1,5-a][1,3,5]triazine-8-carboxylic acid ethyl ester.
Scheme 67: Microwave-assisted synthesis of 4,7-dihetarylpyrazolo[1,5-a][1,3,5]triazines.
Scheme 68: Alternative synthetic route to 4,7-diheteroarylpyrazolo[1,5-a][1,3,5]triazines.
Scheme 69: Synthesis of 4-aryl-2-ethylthio-7-methylpyrazolo[1,5-a][1,3,5]triazines.
Scheme 70: Microwave-assisted synthesis of 4-aminopyrazolo[1,5-a][1,3,5]triazine.
Scheme 71: Synthesis of pyrazolo[3,4-d][1,2,3]triazines from pyrazol-5-yl diazonium salts.
Scheme 72: Synthesis of 2,5-dihydropyrazolo[3,4-e][1,2,4]triazines.
Scheme 73: Synthesis of pyrazolo[5,1-c][1,2,4]triazines via diazopyrazolylenaminones.
Scheme 74: Synthesis of pyrazolo[5,1-c][1,2,4]triazines in presence of sodium acetate.
Scheme 75: Synthesis of various 7-diazopyrazolo[5,1-c][1,2,4]triazine derivatives.
Scheme 76: One pot synthesis of pyrazolo[5,1-c][1,2,4]triazines.
Scheme 77: Synthesis of 4-amino-3,7,8-trinitropyrazolo-[5,1-c][1,2,4]triazines.
Scheme 78: Synthesis of tricyclic pyrazolo[5,1-c][1,2,4]triazines by azocoupling reaction.
Approaches towards the synthesis of 5-aminopyrazoles
- Ranjana Aggarwal,
- Vinod Kumar,
- Rajiv Kumar and
- Shiv P. Singh
Beilstein J. Org. Chem. 2011, 7, 179–197, doi:10.3762/bjoc.7.25
Graphical Abstract
Figure 1: Pharmacologically active 5-aminopyrazoles.
Scheme 1: General equation for the condensation of β-ketonitriles with hydrazines.
Scheme 2: Reaction of hydrazinoheterocycles with α-phenyl-β-cyanoketones (4).
Scheme 3: Condensation of cyanoacetaldehyde (7) with hydrazines.
Scheme 4: Synthesis of 5-aminopyrazoles and their sulfonamide derivatives.
Scheme 5: Synthesis of 5-aminopyrazoles, containing a cyclohexylmethyl- or phenylmethyl- sulfonamido group at...
Scheme 6: Regioselective synthesis of 3-amino-2-alkyl (or aryl) thieno[3,4-c]pyrazoles 19.
Scheme 7: Solid supported synthesis of 5-aminopyrazoles.
Scheme 8: Synthesis of 5-aminopyrazoles from resin supported enamine nitrile 25 as the starting material.
Scheme 9: Two-step “catch and release” solid-phase synthesis of 3,4,5-trisubstituted pyrazoles.
Scheme 10: Synthesis of pyrazolo[5,1-d][1,2,3,5]tetrazine-4(3H)-ones.
Scheme 11: Synthesis of the 5,5-ring system, imidazo[1,2-b]pyrazol-2-ones.
Scheme 12: Synthesis of 5-amino-3-(pyrrol-2-yl)pyrazole-4-carbonitrile.
Scheme 13: Synthesis of N-(1,3-diaryl-1H-pyrazol-5-yl)benzamide.
Scheme 14: Synthesis of 3,7-bis(arylazo)-6-methyl-2-phenyl-1H-imidazo[1,2-b]pyrazoles.
Scheme 15: Synthesis of 3,5-diaminopyrazole.
Scheme 16: Synthesis of 5-amino-4-cyanopyrazole and 5-amino-3-hydrazinopyrazole.
Scheme 17: Synthesis of 3,5-diaminopyrazoles with substituted malononitriles.
Scheme 18: Synthesis of 3,5-diamino-4-oximinopyrazole.
Scheme 19: Synthesis of 4-arylazo-3,5-diaminopyrazoles.
Scheme 20: Synthesis of 3- or 5-amino-4-cyanopyrazoles.
Scheme 21: Synthesis of triazenopyrazoles.
Scheme 22: Synthesis of 5(3)-aminopyrazoles.
Scheme 23: Synthesis of 3-substituted 5-amino-4-cyanopyrazoles.
Scheme 24: Synthesis of 2-{[(1-acetyl-4-cyano-1H-pyrazol-5-yl)amino]methylene}malononitrile.
Scheme 25: Synthesis of 5-aminopyrazole carbodithioates and 5-amino-3-arylamino-1-phenylpyrazole-4-carboxamide...
Scheme 26: Synthesis of 5-amino-4-cyanopyrazoles.
Scheme 27: Synthesis of thiazolylpyrazoles.
Scheme 28: Synthesis of 5-amino-1-heteroaryl-3-methyl/aryl-4-cyanopyrazoles.
Scheme 29: Synthesis of 5-amino-3-methylpyrazole-4-carboxamide.
Scheme 30: Synthesis of 4-acylamino-3(5)-amino-5(3)-arylsulfanylpyrazoles.
Scheme 31: Synthesis of 5-amino-1-aryl-4-diethoxyphosphoryl-3-halomethylpyrazoles.
Scheme 32: Synthesis of substituted 5-amino-3-trifluoromethylpyrazoles 114 and 118.
Scheme 33: Solid-support synthesis of 5-N-alkylamino and 5-N-arylaminopyrazoles.
Scheme 34: Synthesis of 5-amino-1-cyanoacetyl-3-phenyl-1H-pyrazole.
Scheme 35: Synthesis of 3-substituted 5-amino-1-aryl-4-(benzothiazol-2-yl)pyrazoles.
Scheme 36: Synthesis of 5-amino-4-carbethoxy-3-methyl-1-(4-sulfamoylphenyl)pyrazole.
Scheme 37: Synthesis of inhibitors of hsp27-phosphorylation and TNFa-release.
Scheme 38: Synthesis of the diglycylpyrazole 142.
Scheme 39: Synthesis of 5-amino-1-aryl-4-benzoylpyrazole derivatives.
Scheme 40: Synthesis of 4-benzoyl-3,5-diamino-1-(2-cyanoethyl)pyrazole.
Scheme 41: Synthesis of the 5-aminopyrazole derivative 150.
Scheme 42: Synthesis of 3,5-diaminopyrazoles 153.
Scheme 43: Synthesis of 5-aminopyrazoles derivatives 155 via lithiated intermediates.
Scheme 44: Synthesis of 5-amino-4-(1,2,4-oxadiazol-5-yl)-pyrazoles 157.
Scheme 45: Synthesis of a 5-aminopyrazole with anticonvulsant activity.
Scheme 46: Synthesis of tetrasubstituted 5-aminopyrazole derivatives.
Scheme 47: Synthesis of substituted 5-aminopyrazoles from hydrazonoyl halides.
Scheme 48: Synthesis of 3-amino-5-phenylpyrazoles from isothiazoles.
Scheme 49: Synthesis of 5-aminopyrazoles via ring transformation.
