Formation of spiro[indene-2,3′-pyrazole] derivatives from hydrazonyl chlorides and ninhydrin-malononitrile adduct

Abstract

An efficient synthesis of spiro[indene-2,3 0 -pyrazole] derivatives via a three-component reaction between ninhydrin, malononitrile, and hydrazonyl chlorides in EtOH at room temperature is described. Graphical abstract EtOH, 6 h N N H Cl R 1 R 2 O O OH OH CN CN Et 3 N N N O O R 2 CN CN R 1

Advances in the Synthesis of Heterocycles with Two and Three Heteroatoms using Hydrazonoyl Halides

“…Under the conditions of the same reaction medium, nitrilimine is generated in situ from the hydrazonoyl halide, which can easily enter into a cycloaddition reaction with this olefin. The reaction of ninhydrin 155 with malononitrile 156 produces this nominal condensation product 157 , which undergoes a (2+3) cycloaddition reaction with nitrilimine 158 generated in situ from hydrozonyl chloride 159 , leading to spiro‐linked indanedione‐pyrazoles 160 in high yields ( Scheme 49) [110] …”

“…The reaction of ninhydrin 155 with malononitrile 156 produces this nominal condensation product 157, which undergoes a (2 + 3) cycloaddition reaction with nitrilimine 158 generated in situ from hydrozonyl chloride 159, leading to spiro-linked indanedione-pyrazoles 160 in high yields (Scheme 49) . [110] Transformations in the reaction mixture consisting of hydrazonoyl chloride 161, dihydrogenated arylideneindazolones 162 and triethylamine upon boiling in benzene culminate in the formation of spirocyclic compounds 163 (Scheme 50). [111] The yields of cycloaddition products differ slightly; a decrease in productivity to 50 and 55 % was noted in the case of spirocycles 163 with substituents Ar=4-F-and 4-ClÀ C 6 H 4 .…”

Simple synthesis of new imidazopyridinone, pyridopyrimidinone, and thiazolopyridinone derivatives and optimization of reaction parameters using response surface methodology

“…[7][8][9][10] Among these heterocycles, pyridine derivatives, such as imidazopyridine, pyridopyrimidine, and thiazolopyridine derivatives have received considerable attention over the past years due to their diverse biological activities and clinical applications. 11,12 Imidazopyridine derivatives have shown a broad range of interesting biological activities, such as antifungal, antitumor, antiviral, antibacterial, anti-HIV, 13 antipyretic, analgesic, hypnoselective, anxioselective, anti-inammatory, anticonvulsant, antiulcer, immunomodulatory 14 activities; also pyridopyrimidine derivatives 15 are found to exhibit a broad spectrum of potent antibacterial, antiallergic, antimicrobial, 12 anti-inammatory, analgesic, 16,17 tyrosine kinase, calcium channel antagonists, 8,18 tuberculostatic, antileishmanial, antitumor, 19 antifolate, antihypertensive, hepatoprotective, 20 anticancer 21 properties; and thiazolopyridine derivatives are associated with a wide range of biological activities such as analgesic, antioxidant, 11 anticancer, 22 anti-inammatory, 23 antihypertensive, 24 antibacterial, and antifungal 25,26 properties.…”

Synthesis of Spiro[indoline‐3,4′‐pyrano[3,2‐c]chromene]diones

“…Spiro heterocycles represent an important class of naturally occurring substances with biological activities and diversified pharmacological and therapeutical properties . In recent years, isatin‐related articles have been published on synthesis of spiro and multispiro heterocyclic compounds from isatin .…”