Resorcinol Derivatives Research Articles

ChemInform Abstract: Regioselective Lithiation of Resorcinol Derivatives: Synthesis of Mono O‐MOM‐ and O‐Benzylresorcinols Prenylated at C‐2 or C‐4 Positions

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Regioselective Lithiation of Resorcinol Derivatives: Synthesis of Mono O-MOM- and O-Benzylresorcinols Prenylated at C-2 or C-4 Positions

Regioselective Lithiation of Resorcinol Derivatives: Synthesis of Mono O-MOM- and O-Benzylresorcinols Prenylated at C-2 or C-4 Positions

Binding Properties of Two Novel Phosphane-Modified Tetrapodants and Their Bimetallic Transition Metal Complexes

Two novel phosphane ligands 3 and 4 based on the rigid diphenylglycoluril molecule have been synthesized and characterised. Binding studies with 3 and 4, using 1,3-dihydroxybenzene derivatives reveal that ligands 3 and 4 behave similarly to clip molecule 5, which has the same binding site as ligands 3 and 4. The size of the flexible spacers in the ligands has been varied and the effect of this variation on the association constant of resorcinol derivatives has been determined. These cavity-containing ligands are able to coordinate two transition metal centres, leading to bimetallic macrocycles. The metallamacrocycles formed from 4 containing platinum or rhodium bind the guest, olivetol (5-pentylbenzene-1,3-diol), almost four times as strongly as the free tetrapodant 4. Complexes of 4 having palladium centres display similar or reduced binding affinities for resorcinol derivatives, when compared to free 4. Metal complexes of ligand 3 do not form host-guest complexes, probably because of a too small a ring-size of the metallamacrocycle.

ChemInform Abstract: Synthesis of 5‐Substituted Resorcinol Derivatives via Cross‐Coupling Reactions.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis of 5-Substituted Resorcinol Derivatives via Cross-Coupling Reactions

Suzuki and Stille cross-coupling reactions were utilized in the synthesis of 5-substituted 1,3-dimethoxybenzene and 5-substituted resorcinol derivatives. The substituted resorcinol derivatives were obtained in only three steps from inexpensive reagents. 1,3-Dimethoxybenzoic acid and 1-chloro-3,5-dimethoxybenzene were transformed into 1-iodo-, 1-bromo-, 1-trimethyltin-3,5-dimethoxybenzene and 3,5-dimethoxyphenyl boronic acid. 5-Allyl-1,3-dimethoxybenzene and 3,5-dimethoxybiphenyl derivatives were obtained via cross coupling reactions under mild conditions. HI, BBr3 and AlI3 were used to demethylate these dimethoxybenzenes into their resorcinol derivatives.

Synthesis of 5-Substituted Resorcinol Derivatives via Cross-Coupling Reactions

Suzuki and Stille cross-coupling reactions were utilized in the synthesis of 5-substituted 1,3-dimethoxybenzene and 5-substituted resorcinol derivatives. The substituted resorcinol derivatives were obtained in only three steps from inexpensive reagents. 1,3-Dimethoxybenzoic acid and 1-chloro-3,5-dimethoxybenzene were transformed into 1-iodo-, 1-bromo-, 1-trimethyltin-3,5-dimethoxybenzene and 3,5-dimethoxyphenyl boronic acid. 5-Allyl-1,3-dimethoxybenzene and 3,5-dimethoxybiphenyl derivatives were obtained via cross coupling reactions under mild conditions. HI, BBr3 and AlI3 were used to demethylate these dimethoxybenzenes into their resorcinol derivatives.

Effects of certain resorcinol derivatives on the tyrosinase activity and the growth of melanoma cells.

Effects of certain resorcinol derivatives on tyrosinase activity, melanin formation and some other biological activities were studied in order to develop a new, potent depigmentor and/or antimelanoma drug. NKO-09, having isopentyl group in position 6 of resorcinal, exhibited a more potent effect than the compounds which have methyl (NKO-10), ethyl (NKO-11), hexyl (KOM-14), octyl (NKO-14), decyl (NKO-19), dodecyl (NKO-15) and tetradecyl (NKO-16) group in inhibiting the tyrosinase activities (both tyrosine hydroxylation and dopa oxidation). NKO-09 was more potent than hydroquinone in inhibiting the tyrosine hydroxylation; furthermore, NKO-09 inhibited the dopa oxidation different from hydroquinone. In the studies on melanin formation, protein synthesis and the growth of the melanoma cells, NKO-09 caused the most potent effect among the test compounds, except for the growth of the melanoma cells. KOM-14 was more potent than NKO-09 in the antimelanoma activity, and its effect was superior than that of 5-fluorouracil. From these findings, it is suggested that NKO-09 and KOM-14 can be used as an efficacious depigmentor and antimelanoma drug, respectively.

Synthesis of thiazole‐containing benzo‐crown ethers

AbstractA series of benzo‐crown ethers containing the thiazole subcyclic moity have been synthesized. Reaction of 1,2‐bis(thioamidomethyloxy)benzene 2 with ethyl bromopyruvate in ethanol provided 1,2‐bis(thiazolyl)benzene 4 (80%) along with thiazole 5 (14%). Reduction of 4 with lithium aluminum hydride followed by mesylationbromination gave 7. Similar treatment of 5 with lithium aluminum hydride followed by bromination resulted in 12. Benzo‐crown ethers 8, 9, 10, and 13 were prepared from the reactions of 4‐bromomethylthiazole derivatives 7 and 12 with catechol and resorcinol derivatives in the presence of potassium hydride.

A spontaneous phase transition from reverse micelles to organogels due to surfactant interactions with specific benzenediols

Hydrogen-bonding interactions between suitable phenols and the head group of the twin-tailed anionic surfactant sodium bis(2-ethylhexyl)sulfosuccinate (AOT), form the basis for a novel class of organogels. The gels are novel in that very small quantities of these low molecular weight solutes are sufficient to cause gelation. Previous work has shown that the gel-forming propensity of the phenol is determined by its acid strength and also the substitution pattern on the aromatic ring. Evidence suggests that the underlying molecular architecture of these gels consists of strands of stacked and motionally restricted phenol molecules. The surfactant appears to be linked through hydrogen bonding to the external surface of the stack and its motion is relatively unrestricted. Here, we report the finding that the gels also form with select benzenediols (resorcinol derivatives). Interestingly, these gels are much stronger than some of the strongest gels made with phenols under similar conditions. A combination of NMR and FTIR spectroscopic evidence suggests that these gels derive their strength from binding with both carbonyl groups of the surfactant, whereas in the gels made with phenols, only one carbonyl group is bound. The stacked phenol microstructure of the organogels proposed previously seems to be generally valid for the case of gels formed with the benzenediols. The additional possibility of bridging the adjacent phenol molecules in the stack by the adsorbed surfactant allows for a “scaffolding” around the aromatic stack.

Resorcinol Derivatives and Flavonoids of Ononis natrix Subspecies ramosissima

From extracts of Ononis natrix subsp. ramosissima two new resorcinol derivatives, 5-(2-acetoxy-8-oxotridecyl)resorcinol (1) and 5-(2-acetoxy-7-hydroxy-8-oxotridecyl)resorcinol (2) were isolated and identified, as well as chavicol β-d-glucoside, betulaprenol 6 (13), two steroids, four chalcones, six dihydrochalcones, two flavanones, and three pterocarpans.

Alkyl 2‐(2‐benzoyl‐2‐ethoxycarbonyl‐1‐ethenyl)amino‐3‐dimethylaminopropenoates in the synthesis of heterocyclic systems

AbstractAlkyl 2‐(2‐benzoyl‐2‐ethoxycarbonyl‐1‐ethenyl)amino‐3‐dimethylaminopropenoates 4a,b were prepared. They react with C‐nucleophiles such a 2‐pyridinylacetonitrile 5 and methyl‐2‐quinolinylacetate 8, cyclohexane‐1,3‐dione 10 and its derivatives 12 and 14, resorcinol derivative 16, 2‐naphtol 18, 2‐pyranone derivatives 20 and 22, and 4‐hydroxypyridin‐2(1H)‐one 24, to form substituted amino derivatives of quinolizine 6, benzo[c]quinolizine 9, tetrahydrobenzopyran‐2‐one 11, 13, 15, naphto[2,1‐b]pyran‐3‐one 19, pyranopyranones 21, 23, and pyrano[3,2‐c]pyridine 25.

Resorcinol Derivatives from TwoArdisiaSpecies

Besides a series of known sterols and triterpenoids, 2-methyl-5-(Z-nonadec-14-enyl)resorcinol and 5-(Z-nonadec-14-enyl)resorcinol have been isolated from leaves of Ardisia silvestris. The last mentioned diphenol has also been obtained from roots of Ardisia gigantifolia. The structures of these resorcinol derivatives were elucidated.

ChemInform Abstract: Synthesis and Structure of 13‐ and 26‐Membered Crown Derivatives of Resorcinol

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis and structure of 13- and 26-membered crown ethers, derivatives of resorcinol

13- and 26-Membered crown ethers have been synthesized based on resorcinol and 1,8-dichloro-3,6-dioxaoctane. The products with substituents in the benzene ring have been prepared by alkylation of 13-membered crown ether. Complexing properties of the macrocycles have been studied with the use of ion-selective membrane electrodes. The structures of 13- and 26-membered crown ethers have been established by X-ray structural analysis.

Involvement of phosphorylase kinase inhibition in the effect of resorcinol and proglycosyn on glycogen metabolism in the liver.

The purpose of this study was to identify the mechanism by which proglycosyn and resorcinol decrease the phosphorylase a content and the fructose 2,6-bisphosphate concentration in isolated hepatocytes. The intracellular concentrations of the glucuronide derivatives of proglycosyn and resorcinol have been measured by HPLC in hepatocytes incubated for 5 min or 30 min with different concentrations of these agents. At both times, there was a reciprocal relationship between the phosphorylase a content and the intracellular concentration of the glucuronidated metabolites, half-maximal inactivation being observed at about 2 mumol/g protein and 0.25 mumol/g protein for resorcinylglucuronide and proglycosyn-glucuronide, respectively. Glycogen synthase was not significantly activated by these agents after 5 min but was well activated after 30 min. Preincubation of hepatocytes with 1 mM resorcinol or with 100 microM proglycosyn resulted in a decrease in the rate at which phosphorylase was activated following the addition of glucagon, vasopressin, the protein phosphatase inhibitor calyculin A or the calcium ionophore A 23187, but did not reduce the rate of synthase inactivation. Proglycosynglucuronide and resorcinylglucuronide inhibited phosphorylase kinase in liver Sephadex filtrates, with Ki values of about 0.75 mM and 4 mM, respectively. Preincubation of the filtrates with ATP and cAMP decreased the sensitivity of phosphorylase kinase to resorcinylglucuronide by about fourfold. It is concluded that the effect of resorcinol and proglycosyn on the phosphorylase a content is due, at least partly, to an inhibition of phosphorylase kinase by their glucuronidated metabolites. Resorcinol and proglycosyn caused a parallel decrease in the concentration of fructose 2,6-bisphosphate and of hexose 6-phosphates, without significantly changing the activity of 6-phosphofructo-2-kinase. The decrease in the fructose 2,6-bisphosphate concentration appears therefore to be secondary to the decrease in the hexose 6-phosphate concentration.

Guest-Binding Properties of Organic Crystals Having an Extensive Hydrogen-Bonded Network: An Orthogonal Anthracene-Bis(resorcinol) Derivative as a Functional Organic Analog of Zeolites

Guest-Binding Properties of Organic Crystals Having an Extensive Hydrogen-Bonded Network: An Orthogonal Anthracene-Bis(resorcinol) Derivative as a Functional Organic Analog of Zeolites

Synthese und Eigenschaften von Makrocyclen aus Resorcinen sowie von entsprechenden Derivaten und Wirt‐Gast‐Komplexen

Synthesis and Properties of Macrocycles from Resorcinol, Corresponding Derivatives and Host‐Guest ComplexesStructural variations of the metacyclophanes obtained from the condensation of resorcinol with aldehydes RCHO are described, mostly based on the stereoisomer with all R in cis configuration. The basic tetraphenolate (with R = CH3, 1a) shows a cone‐conformation as evident e.g. from vicinal 13C–C–C–1H coupling constants. Substituents R′ in the 2‐position of the phenyl rings at the upper rim of the macro‐cycle are either introduced with the resorcinol derivative used (R′ = CH3, COOH), or by Mannich reactions after cyclization (R′ = CH2NR″2), which partially lead to intermediate oxacine formation. Acid‐base properties are evaluated with potentiometric and NMR‐shift titrations. Mannich products from amino acids such as proline, which are formed without racemization, show no pK differences for the groups at the four equivalent phenyl rings, but three distinct pK values for the deprotonation of OH, COOH, and +NH3 substituents; the pK of the latter is two units lower than in proline itself as it is involved in hydrogen bridging. Complexation constants K of such derivatives with Fe3+, Cu2+, and Zn2+ show the expected increase with metal ion acidity; they are increased by a power of 5 in comparison to proline. Complexation constants and complexation‐induced NMR shifts (CIS values) are determined for 51 complexes, with positively charged organic guest molecules for the basic tetraphenolate skeleton as well as for the aminomethylation derivatives. A temperature dependence study shows that the corresponding equilibrium is driven by ΔH with negligible ΔS contributions. No chiral discrimation is observed upon complexation of e.g. carnitine with the optically active amino acid derivatives. This is in line with CIS and K values obtained with several complexes showing an orientation of the NR″2 groups away from the cavity. The COOH substituents R′ form strong hydrogen bonds with the adjacent phenolic groups, leading to alternating pseudo‐eq and ‐ax positions of the phenyl rings. Their interconversion barrier, determined by NMR spectroscopy, is 72 kJ mol‐1; they bind mono‐ and bis‐ammonium ions as function of distance matching. The presence of lipophilic substituents (R = phenyl, benzyl, biphenyl, n‐hexyl, n‐undecyl) at the bottom of the macrocycle furnishes a second binding center which allows to complex e.g. diethyl ether in water. Coordination of zinc to the proline derivative still allows co‐complexation of choline acetate, the hydrolysis of which is not inhibited anymore as it is by the zinc‐free macrocycle.

Resorcinol derivatives and other components from Ononis viscosa subsp. breviflora

Seven alkylresorcinols, three alkylbenzoic acids, five alkylisocoumarins, the pterocarpans, variabilin and anhydrovariabilin, and 13′-docosenoylanthranilic acid were identified in the chloroform extract of Ononis viscosa subsp. breviflora.

Spectral analysis of highly symmetric azo phenol, catechol, resorcinol, quinol and pyrogallol derivatives of melamine

Spectral analysis of highly symmetric azo phenol, catechol, resorcinol, quinol and pyrogallol derivatives of melamine

A Novel Type of Cycloaddition Reaction of Silylketenes with Enamines

Enamines underwent a novel type of cycloaddition reaction with excess of silylketenes to give resorcinol derivatives.