A Review on the Recent Multicomponent Synthesis of Pyranopyrazoles

Figures & data

Figure 1. Pyranopyrazole isomers.

Figure 2. Potential inhibitor of human Chk1 kinase.

Scheme 1. Catalyst-free synthesis of a series of pyrano[2,3-c]pyrazoles.

Scheme 2. Synthesis of pyrano[2,3-c]pyrazole derivatives under solvent and catalyst-free conditions.

Scheme 3. Preparation of pyrano[2,3-c]pyrazoles in aqueous ethanol medium under catalyst-free conditions.

Scheme 4. Synthesis of spiro-pyrano[2,3-c]pyrazoles in aqueous ethanol medium under catalyst-free conditions.

Scheme 5. Four-component catalyst-free synthesis of methyl 6-amino-5-cyano-4-aryl-2,4-dihydropyrano[2,3-c]pyrazole-3-carboxylates in water.

Scheme 6. Catalyst-free synthesis of a series of spiro-pyranopyrazoles in aqueous medium.

Scheme 7. Catalyst-free synthesis of 6-amino-4-aryl-3-methyl-2,4-dihydropyrano[2,3-c]pyrazolecarbonitriles in boiling wather.

Scheme 8. Catalyst-free synthesis of pyrano[2,3-c]pyrazole derivatives in water/ethanol at 60 °C.

Scheme 9. Catalyst-free synthesis of spiro-pyrano[2,3-c]pyrazole derivatives in water/ethanol at 60 °C.

Scheme 10. Catalyst-free synthesis of 6-amino-4-aryl-3-(trifluoromethyl)-1,4-dihydro-1-phenylpyrano[2,3-c]pyrazole-5-carbonitriles in aqueous media.

Scheme 11. Catalyst-free synthesis of dihydropyrano[2,3-c]pyrazoles using ball milling technique

Scheme 12. Catalyst-free synthesis of pyrazolo[4',3':5,6]Pyrano[2,3-d]Pyrimidines.

Scheme 13. Synthesis of the pyrano[2,3-c]pyrazole and pyrano[4',3':5,6]pyrazolo [2,3-d]pyrimidine derivatives using magnetized water.

Scheme 14. Solvent-free synthesis of thioether containing dihydropyrano[2,3-c]pyrazoles.

Scheme 15. Synthesis of pyrano[2,3-c]pyrazoles in the presence of silicotungstic acid.

Scheme 16. Synthesis 6-amino-4-aryl-5-cyano-2,4-dihydropyrano[2,3-c]pyrazole-3-carboxylates by a four-component reaction in the presence of acetic acid.

Scheme 17. Preparation of pyrido[2,3-c]pyrazoles using HPA supported onto the silica coated NiFe₂O₄ MNPs (NFS-PRS).

Scheme 18. The use of 1-(carboxymethyl)pyridiniumiodide {[cmpy]I} for the green synthesis of 6-amino-4-(4-methoxyphenyl)-5-cyano-3-methyl-1-phenyl-1,4 dihydropyrano[2,3-c]pyrazoles.

Scheme 19. Synthesis of pyrano[2,3-c]pyrazoles using montmorillonite-K10.

Scheme 20. Synthesis of thioether linked pyranopyrazoles using Montmorillonite K-10.

Scheme 21. The use of aqueous solution of boric acid for the synthesis of pyrano[2,3-c]pyrazoles.

Scheme 22. Synthesis of 4,3'-spiro[(6-amino-5-R-3-methyl-2,4-dihydropyrano[2,3-c]-pyrazolo)-2'-oxindoles] using triethanolamine.

Scheme 23. Preparation of 6-amino-5-cyano-3-methyl-4-aryl/heteroaryl-2H,4H-dihydropyrano[2,3-c]pyrazoles in the presence of piperidine.

Scheme 24. Synthesis of dihydropyrano[2,3-c]pyrazoles in EtOH at room temperature.

Scheme 25. Four-component synthesis of 6-amino-2H,4Hpyrano[2,3-c]pyrazol-5-carbonitriles using aromatic aldehyde.

Scheme 27. Synthesis of spiro-conjugated 6-amino-2H,4H-pyrano[2,3-c]pyrazol-5-carbonitriles.

Scheme 28. Changing the sequence of reactants in the reaction with isatine.

Scheme 29. Piperidine catalyzed synthesis of spiro[indoline-3,4'-pyrano[2,3-c]pyrazole]-5'-carbonitriles.

Scheme 30. Piperidine catalyzed synthesis of spiro[acenaphthylene-1,4'-pyrano[2,3-c]pyrazole]-5'-carbonitrile.

Scheme 31. Synthesis of 3-methyl-4-aryl-4,5-dihydro-1H-pyrano[2,3-c]pyrazol-6-ones in the presence of Ba(OH)₂.

Scheme 32. Preparation of 6-amino-3-methyl-4-aryl-/1-phenyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles using cetyltrimethylammonium chloride (CTACl).

Scheme 33. Base catalyzed synthesis of spiro[indoline-3,4'-pyrano[2,3-c]pyrazole]-3'-carboxylate derivatives.

Scheme 26. Four-component synthesis of pyrano[2,3-c]pyrazole using saturated heterocyclic ketones.

Scheme 34. Synthesis of pyrano[2,3-c]pyrazoles in the presence of sodium benzoate.

Figure 3. (E)-N-Methyl-1-(methylthio)-2-nitroethenamine (NMSM).

Scheme 35. (E)-N-Methyl-1-(methylthio)-2-nitroethenamine (NMSM) as an ambiphilic synthon for the synthesis of pyrano[2,3-c]pyrazoles.

Scheme 36. Preparation of 6-amino-5-cyano-2′-oxo-5′-phenyl-1′,2′-dihydro-1H-spiro[pyrano[2,3-c]pyrazole-4,3′-pyrroles] in the presence of NEt₃.

Scheme 37. Synthesis of coumarin based pyrano[2,3-c]pyrazole derivatives using DMAP (4-dimethylaminopyridinein).

Scheme 38. Diethyl oxalacetate sodium salt as a reagent for the synthesis of spiro[indoline-3,4'-pyrano[2,3-c]pyrazoles].

Scheme 39. A plausible mechanism for the preparation of spiro[indoline-3,4'-pyrano[2,3-c]pyrazoles].

Scheme 40. Application of N,N-Diisopropylethylamine (DIPEA) for the synthesis of 1,4-dihydropyrano[2,3-c]pyrazol-6-amines.

Scheme 42. Synthesis of spiro-pyrano[2,3-c]pyrazoles in the presence of DCDBTSD.

Scheme 43. NMO and Ag₂O catalyzed synthesis of pyrano[2,3-c]pyrazoles.

Scheme 44. Synthesis of pyranopyrazoles in the presence of glycine.

Scheme 46. Synthesis of spiro-pyrano[2,3-c]pyrazoles using β-CD.

Scheme 47. Synthesis of 6'-amino-1-(4-(6'-amino-5'-cyano-3'-methyl-2-oxo-1'H-spiro[indoline-3,4'-pyrano[2,3-c]pyrazol]-1-yl)butyl)-3'-methyl-2-oxo-1'H-spiro[indoline-3,4'-pyrano[2,3-c]pyrazole]-5'-carbonitrile in the presence of β-CD.

Scheme 48. Per-6-amino-β-cyclodextrin (per-6-ABCD) as catalyst for the synthesis of dihydropyrano[2,3-c]pyrazole derivatives.

Scheme 41. Synthesis of 1,4-dihydropyrano[2,3-c]pyrazoles using N,2-dibromo-6-chloro-3,4-dihydro-2H-benzo[e][1,2,4] thiadiazine-7-sulfonamide-1,1-dioxide (DCDBTSD).

Scheme 49. Synthesis of pyrano[2,3-c]pyrazoles using imidazole.

Scheme 50. Urea catalyzed synthesis of 1,4-dihydropyrano[2,3-c]pyrazoles.

Scheme 51. Enantioselective synthesis of 6-amino-5 cyanodihydropyrano[2,3-c]pyrazoles using cupreine (37).

Figure 4. Cocamidopropyl betaine (CAPB).

Scheme 52. Synthesis of dihydropyrano[2,3-c]pyrazoles using cocamidopropyl betaine (CAPB).

Scheme 45. Synthesis of pyrano[2,3-c]pyrazoles using β-CD.

Scheme 53. Isonicotinic acid catalyzed synthesis of 1,4-dihydropyrano[2,3-c]pyrazoles.

Scheme 54. Synthesis of pyrano[2,3-c]pyrazole using bleaching earth clay.

Scheme 55. Synthesis of pyrazolopyranopyrimidines in the presence of DABCO.

Scheme 56. Synthesis of dihydropyrano[2,3-c]pyrazole derivatives using DABCO.

Scheme 57. Preparation of bis-pyranopyrazoles in the presence of DABCO.

Scheme 58. Synthesis of 1,4-dihydropyrano[2,3-c]pyrazoles using organocatalysts.

Scheme 59. Grinding protocol for the synthesis of dihydropyrano[2,3-c]pyrazole using L-proline.

Scheme 61. Synthesis of spiro[indoline-3,4' pyrano[2,3-c]pyrazole] derivatives using meglumine.

Scheme 62. Preparation of spiro[acenaphthylene-1,4'-pyrano[2,3-c]pyrazole] meglumine using meglumine.

Scheme 63. The use of maltose to synthesis of 1,4-dihydropyrano[2,3-c]pyrazoles.

Scheme 64. Application of sucrose to synthesis of 1,4-dihydropyrano[2,3-c]pyrazoles.

Figure 5. Ammonium triflates.

Scheme 65. The use of morpholine triflate (MorT) to prepare dihydropyrano[2,3-c]pyrazoles.

Scheme 66. Synthesis of pyrano[2,3-c]pyrazole derivatives using Bovine Serum Albumin (BSA).

Scheme 67. Synthesis of spiro[indoline-3,4'-pyrano[2,3-c]pyrazole] derivatives in the presence of TBBDA or PBBS.

Scheme 60. Synthesis of a series of dihydroprano[2,3-c]pyrazoles in the presence of meglumine.

Scheme 68. Synthesis of pyrano[2,3-c]pyrazoles in the presence of Ph₃CCl.

Scheme 69. Dihydropyrano[2,3-c]pyrazoles and spiro-pyranopyrazoles in the presence of aspirin.

Scheme 70. Five-component reaction for the synthesis a series of biaryl substituted pyranopyrazoles using Pd/C.

Scheme 71. Four-component synthesis of pyranopyrazoles using a mixed-ligand Ni(II) complex [Ni(L)(mimi)].

Scheme 72. The use of Fe-CaOx for the synthesis of 2,4-dihydropyrano[2,3-c]pyrazoles.

Scheme 73. Synthesis of 6-amino-4-alkyl/aryl-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole-carbonitriles using Amberlyst A21.

Scheme 74. Synthesis of dihydropyrano[2,3-c]pyrazole derivatives using PS-PTSA.

Scheme 75. Utilization of PEG-400 for the synthesis of spiro[indoline-3,4'-pyrano[2,3-c]pyrazole]-3'-carboxylates.

Scheme 76. The use of PEG-400 for the synthesis of trifluoromethylated spiro[indole-3,4'-pyrano[2,3-c]pyrazole] derivatives.

Scheme 77. Preparation of 4H-pyrano[2,3-c]pyrazoles in the presence of L-proline and [Bmim]BF₄.

Scheme 78. The use of [(CH₂)₄SO₃HMIM][HSO₄] for preparation of dihydropyrano[2,3-c]pyrazoles.

Scheme 79. Synthesis of 6-amino-4-(4-methoxyphenyl)-5-cyano-3-methyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles using [Dsim]AlCl₄.

Scheme 80. The use of [TMG][Ac] for the synthesis of dihydro-1H-pyrano[2,3-c]pyrazol-6-ones.

Scheme 81. Synthesis of pyranopyrazoles using 1,4-dimethyl-1-(4-sulphobutyl)piperazinium hydrogen sulfate.

Scheme 82. The use of [ChCl][ZnCl₂]₂ or [H-NMP]HSO₄ for the synthesis of pyrano[2,3-c]pyrazoles.

Figure 6. Synthesis of bis-1,4-dihydro-3-methylpyrano[2,3-c]pyrazole-5-carbonitriles.

Scheme 84. Application of [DMBSI]HSO₄ to the synthesis of spiro-pyrano[2,3-c]pyrazoles.

Figure 7. Preparation of bis-pyrano[2,3-c]pyrazoles using [DMBSI]HSO₄.

Scheme 85. Methyl 4-(aryl)-3-methyl-6-oxo-1,4,5,6-tetrahydropyrano[2,3-c] pyrazole-5- carboxylates using [DMBSI]HSO₄.

Figure 8. Various ionic liquids screened fo the synthesis of pyrano[2,3-c]pyrazole.

Scheme 86. Preparation of pyrano[2,3-c]pyrazoles in the presence of [DMDBSI].2HSO₄

Figure 9. Silica-supported ionic liquids.

Scheme 87. Supported ionic liquids catalyzed synthesis of 3-methyl-4-aryl-4,5-dihydro-1H-pyrano[2,3-c]pyrazol-6-ones.

Scheme 88. The use of supported ionic liquids for the synthesis of pyrazolopyranopyrimidines.

Scheme 89. Preparation of 6-amino-2H,4H-pyrano[2,3-c]pyrazole-5-carbonitriles using DES (choline chloride:urea).

Scheme 90. Synthesis of dihydropyrano[2,3-c]pyrazole in DES medium.

Scheme 83. Synthesis of pyrano[2,3-c]pyrazole derivatives in the presence of [DMBSI]HSO₄.

Scheme 91. Synthesis of 6-amino-4-aryl-2,4-dihydro-3-phenyl pyrano [2,3-c]pyrazole-5-carbonitrile derivatives using choline chloride based thiourea.

Scheme 92. Synthesis of 6-amino-3-alkyl-4-aryl-5-cyano-1,4-dihydropyrano[2,3-c]pyrazoles in the presence of magnesium oxide.

Scheme 93. Synthesis of a series of pyranopyrazoles using magnetic Fe₃O₄ nanoparticles.

Scheme 94. The use of CuFe₂O₄ magnetic nanoparticles for the synthesis of 3-methyl-1,4-dihydropyrano[2,3-c]pyrazoles.

Scheme 95. Preparation of dihydropyrano[2,3-c]pyrazole-3-carboxylate derivatives in the presence of CuFe₂O₄ magnetic nanoparticles.

Scheme 96. The proposed mechanism for the formation of products 60 and 61.

Scheme 97. The use of nano titanium dioxide for preparation of 6-amino-4-aryl-3-methyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles.

Scheme 98. Application of ZrO₂ nanoparticles as catalyst in the synthesis of pyrano[2,3-c]pyrazoles.

Scheme 99. Preparation of pyranopyrazoles in the presence of Ni_0.5Zn_0.5Fe₂O₄@Hap-Cs₂CO₃.

Scheme 100. Synthesis of pyranopyrazoles using Ag nanoparticles.

Scheme 101. The use of ZnS nanoparticles for preparation of 4H-pyrano[2,3-c]pyrazoles by grinding.

Scheme 102. The use of BF₃/MNPs nanoparticles for preparation of 1,4-dihydropyrano[2,3-c]pyrazole derivatives.

Scheme 103. Synthesis of pyran[2,3-c]pyrazoles in the presence of Fe₃O₄@SiO₂ core-shell nanocatalyst.

Scheme 104. Preparation of 1,4-dihydropyrano[2,3-c]pyrazoles using Fe_3-xTi_xO₄@SO₃H nanoparticles.

Scheme 105. Synthesis of 3-methyl-4-phenyl-1,4-dihydropyrazolo[4',3':5,6]pyrano[2,3-d]pyrimidine-5,7(6H,8H)-dione derivatives.

Scheme 106. Preparation of MMT-ZSA.

Scheme 107. Synthesis of pyranopyrazoles using MMT-ZSA.

Scheme 108. Synthesis of dihydropyrano[2,3-c]pyrazole in the presence of Ag/TiO₂ nano-thin films.

Scheme 109. Synthesis of pyrano[2,3-c:6,5-c']dipyrazol]-2-ones using Ag NPs/rGO composite.

Scheme 110. The use of Ni_0.5Zn_0.5Fe₂O₄ (Ni_0.5Zn_0.5Fe₂O₄–PPA) for preparation of 5-cyano-1,4-dihydropyrano[2,3-c]pyrazoles.

Scheme 111. Synthesis of pyrano[2,3-c]pyrazole in the presence of SiO₂ NPs.

Scheme 112. Preparation of nano‐Fe [phenylsalicylaldiminemethylpyranopyrazole]Cl₂ catalyst.

Scheme 113. Synthesis of pyranopyrazoles by using nano‐[Fe‐PSMP]Cl₂.

Scheme 114. The use of Fe₃O₄@SiO₂‐HMTA‐SO₃H MNPs for the synthesis of pyranopyrazoles.

Scheme 115. Synthesis of pyranopyrazoles in the presence of Fe₃O₄/PVAm.

Scheme 116. synthesis of dihydropyrano[2,3-c]pyrazole derivatives in the presence of Fe₃O₄@HNTs-PEI nano-catalyst.

Scheme 118. Synthesis of spiro[indoline-3,4′-pyrano[2,3-c]pyrazole] derivatives using β-CD/EP polymer.

Scheme 119. Preparation of pyranopyrazoles using Fe₂O₃@SiO₂@Vit.B1 NPs.

Scheme 120. Synthesis of pyranopyrazoles using Nd-SM.

Scheme 121. Electrosynthesis of spirocyclic [indole-3,4'-pyrano[2,3-c]pyrazole] compounds.

Scheme 122. Presented mechanism for the electrosynthesis of spirocyclic [indole-3,4'-pyrano[2,3-c]pyrazoles].

Scheme 123. Preparation of pyranopyrazoles by the traditional heating techniques and microwave-assisted reaction.

Scheme 117. Synthesis of the pyranopyrazoles catalyzed by β-CD/EP polymer.

Scheme 124. Synthesis of pyranopyrazoles by traditional heating and microwave-assisted reaction.

Scheme 126. Synthesis of indolylpyrano[2,3-c]pyrazoles under microwave irradiation.

Scheme 127. Synthesis of pyrano[2,3-c] pyrazoles using ([bmim][OH] under microwave irradiation.

Scheme 128. Synthesis of pyranopyrazoles using ZnS nanoparticle under ultrasonic irradiation.

Scheme 129. Synthesis of spiro[indoline-3,4′-pyrano[2,3-c]pyrazole] derivatives in the presence of piperidine under ultrasonic irradiations.

Scheme 130. Preparation of dihydropyrano[2,3-c]pyrazole derivatives in the presence of CAN and under ultrasonic irradiation.

Scheme 131. Preparation of dihydropyrano[2,3-c]pyrazole using molecular sieves (MS 4 Å) under reflux and ultrasonic irradiation.

Scheme 132. Catalyst-free synthesis of pyranopyrazoles under ultrasonic irradiation.

Scheme 125. Synthesis of quinolylpyrano[2,3-c]pyrazoles under microwave irradiation.

Scheme 133. Synthesis of pyrano[2,3-c]pyrazole-3-carboxylate/pyrano[2,3-c]pyrazole-5-carbonitrile using Mn doped zirconia under ultrasonic irradiation.