Catalyst-free alkylation of aminopyrazole by isatin in water

Abstract

Reactions of isatins with 5-aminopyrazole afforded the 3-(5-aminopyrazol-4-yl)-3-hydroxy-2-oxindolines in good to excellent yields in refluxing water. No catalysts were required in the process. The new method exhibited the characteristics including green process, high yields, easy operation, and mild reaction conditions. alkylation, aminopyrazole, isatin, catalyst-free, water Citation:Yang J M, Wu L, Fang D, et al. Catalyst-free alkylation of aminopyrazole by isatin in water.

Synthesis of New Oxindoles and Determination of Their Antibacterial Properties

“…e product 3a, so obtained, did not require further purification with a yield of 69%. Spectroscopic and analytical data (NMR, FT-IR, EI-MS and elemental analysis) of compound 3a matched with the information supplied for the same structure in references [24][25][26][27]. e main 1 H-NMR signals for 3a correspond to the NH 2 protons at 5.28 ppm as a broad singlet, and the hydroxyl proton as a singlet at 6.61 ppm.…”

“…Despite the acceptable-to-good reaction yields (44-96%) obtained in our approach, in comparison with the procedure described by Yang et al [27], remarkably, our methodology required less reaction time and less consumption of energy.…”

“…Balamurugan et al [26] described the synthesis of 3-(4-pyrazolyl)-oxindoles via an InCl 3 -catalyzed tricomponent reaction between arylhydrazines, 3-aminocrotonitrile, and isatin under reflux in water at 100°C. Also, Yang et al synthesized 3-(4-pyrazolyl)oxindoles by a reaction of isatin derivatives and 5-aminopyrazoles under reflux in water [27].…”

A Fluorescence‐Based Assay for N5‐Carboxyaminoimidazole Ribonucleotide Mutase

“…We anticipate that we will have to deal with quenching of the signal by organic compounds and/or the reaction of library compounds with isatin. Unfortunately, uncatalyzed reactions in water of various functional groups with isatin have had limited study [24–26] . The few papers that do discuss these reactions typically involve elevated temperatures along with thiols and hydrazines [24,27–29] .…”

“…Unfortunately, uncatalyzed reactions in water of various functional groups with isatin have had limited study. [24][25][26] The few papers that do discuss these reactions typically involve elevated temperatures along with thiols and hydrazines. [24,[27][28][29] Undoubtedly, we will discover other reactions during screening, and we will report the results of these future studies in due course.…”