New diazadi(and tri)thia‐21‐crown‐7 ethers containing 8‐hydroxyquinoline side arms

Abstract

A series of macrocyclic diazadi(and tri)thiacrown ethers containing two 5-substituent-8-hydroxyquinoline side arms have been synthesized from the corresponding macrocyclic diazadi(and tri)thiacrown ethers. The crown ethers were obtained by reduction of the proper macrocyclic di(and tri)thiadiamides by boranetetrahydrofuran or by sodium borohydride-boron trifluoride ethyl etherate-tetrahydrofuran. The yields for the reduction of diamides by sodium borohydride-boron trifluoride ethyl etherate-tetrahydrofuran were higher than those by borane-tetrahydrofuran. The following four methods were used to prepare macrocycles bearing two 8-hydroxyquinoline side arms: (1) Mannich reaction with 8-hydroxyquinoline; (2) Reductive amination with 8-hydroxyquinoline-2-carboxaldehyde using sodium triacetoxyborohydride as the reducing agent; (3) Cyclization of N,N'-bis(8-hydroxyquinolin-2-ylmethyl)-1,2-bis(2-aminoethoxy)ethane (38) with bis(α-chloroamide) 5; and (4) A step-by-step process wherein macrocyclic trithiadiamide 11 was reduced by lithium aluminum hydride-tetrahydrofuran to the cyclic monoamide 36, which smoothly reacted with 5-chloro-8-hydroxyquinoline to produce monosubstituted-macrocyclic monoamide 39.

Synthesis, Structural Characterization, Experimental, and Computational Spectrophotometric Studies of 8-Quinolinyloxymethyphosphonate Compounds

“…The 8-HQ as well as the 8-AQ (8-aminoquinoline) compounds have been extensively derivatized with metal-binding substituents with the aim of tuning the fluorescence response. − Functional groups that have been attached include 8- p -toluenesulfonamide, as in commercially available TSQ 6 and Zinquin, dansyl, ethylenediamine (in TQEN), tris(2-aminoethyl)amine (in O-TRENSOX), benzothiazole, numerous crown ethers, for example, tri-thia-21-crown-7-ethers, diaza-18-crown-6 ligands, and tetraazacrown ethers …”

Time-Dependent DFT Study of Emission Mechanism of 8-Hydroxyquinoline Derivatives as Fluorescent Chemosensors for Metal Ions

“…BQOH was synthesized from 8-hydroxyquinolinecarboxaldehyde and N-benzylmethylamine [12]. 8-Hydroxyquinolinecarboxaldehyde was prepared by the oxidation of commercially available 2-methyl-8-hydroxyquinoline with selenium dioxide in dioxane [13].…”

“…BQClOH was from 5-chloro-8-hydroxyquinoline and Nbenzylmethylamine [12]. The fluorescence spectra were taken on a Hitachi F-4500 fluorophotometer.…”

Synthesis of Bioactive Aminomethylated 8-Hydroxyquinolines via the Modified Mannich Reaction

“…• C for 10-20 min without solvent, delivering 208a,b[142]. Compound 209 was synthesised by treating azathia-crown ether, 14 and paraformaldehyde in benzene under reflux for 15 h by Song et al[143]. 210 was furnished from 1, 4-azadibenzo 18-crown-6 ether and paraformaldehyde upon stirring in THF at r.t. for 75 h by Mehta et al[144].…”