Reaction Of O-aminophenol Research Articles

GREEN APPROACH FOR THE PREPARATION OF 2-ARYL-1, 3-BENZOXAZOLE DERIVATIVES BY USING Amla Fruit EXTRACT

One pot, rapid and green preparation of 2-aryl-1,3-benzoxazole and their derivatives via the reaction of o-amino phenol and substituted aryl aldehydes by using amla fruit extract at room temperature or under microwave radiation. Amla fruit extract is a biocatalyst associated with low-cost, inexpensive, non-volatile, and environmentally friendly. The prepared catalyst shows many chemical, phytochemical, and anti-oxidant constituents, which are unfavorable to increase the acidic contents of water extract. The noteworthy benefits of this process are simple, easy methodology, an excellent yield of product, minimum time of reaction, ease of separation, easy work, and green catalyst. The prepared compound where characterized by analytical or spectroscopic techniques such as FT-IR (infrared) spectrum, H1-NMR, C13-NMR, and LC-MS (Mass) analysis.

Palladium complexes of NO type Schiff bases: synthesis, characterization and antioxidant activities

The reaction of o-aminophenol with para hydroxy and methoxy substituted benzaldehydes yielded two Schiff bases. These Schiff bases functioning precursors were turned into palladium complexes by treating palladium acetate. The structural formulas based on spectral methods (elemental analysis, FT-IR spectroscopy, NMR spectroscopy and QTOF-LC/MS spectroscopy) were suggested for obtained both complexes. According to the structural characterization methods, one of the complexes had also an acetate co-ligand along with the hydroxy substituted Schiff base ligand. In the other complex, the palladium central ion was proposed to be coordinated with two methoxy substituted Schiff bases. Besides, DPPH scavenging activities of the all synthesized compounds were determined and compared to well-known antioxidant standards. According to the results, antioxidant activities of the palladium complexes was mild but lower than parent Schiff bases.

Elemental sulfur-promoted one-pot synthesis of 2-(2,2,2-trifluoroethyl)benzoxazoles and their derivatives.

A novel and direct strategy has been developed for the synthesis of 2-(2,2,2-trifluoroethyl)benzoxazoles by reaction of o-aminophenols and 2-bromo-3,3,3-trifluoropropene in the presence of elemental sulfur under metal-free conditions. The scope of this methodology was further extended to the synthesis of the trifluoroethylated benzothiazole and benzoimidazole derivatives. A plausible mechanism was proposed on the basis of isolation and characterization of a thioamide intermediate.

Sonocatalyzed facile synthesis of 2-aryl benzoxazoles using MnO2 nanoparticles as oxidant agent under mild conditions

ABSTRACTNano MnO2 was found to be an efficient oxidant agent for the synthesis of 2-substituted benzoxazoles through one-pot reaction of o-aminophenol and different aromatic aldehydes in acetonitrile under ultrasonic irradiation. This method was performed under mild conditions with high yields, inexpensive and readily available oxidant agent, facile and easy experimental procedure, simple purification of final products, and short reaction times. The prepared nano MnO2 has been characterized by FTIR, XRD, and SEM techniques. The pure products were identified and characterized by physical and spectroscopic data such as; melting point, IR, 1H NMR, and 13C NMR.

Selective synthesis of 2-aminobenzoxazoles and 2-mercaptobenzoxazoles by using o-aminophenols as starting material

2-Aminobenzoxazoles and 2-mercaptobenzoxazoles were selectively synthesized by treating o-aminophenols with dithiocarbamates and tetramethylthiuram disulfide (TMTD), respectively. With the promotion of NaH/CuI, the reaction of o-aminophenols with dithiocarbamates gave 2-aminobenzoxazoles with good yield (70–92%) in one pot manner, and 2-mercaptobenzoxazoles were synthesized (yield: 55–80%) in the presence of K2CO3 by treating o-aminophenols with tetramethylthiuram disulfide (TMTD). The feature of this method includes good to excellent yield, easy performance and broad substrate scope, which makes the protocol practical and attractive in the preparation of some potential pharmaceutically active compounds.

Reaction of o-aminophenol and o-aminobenzyl alcohol with palladium(II) bis(isocyanide) complexes

Reactions of palladium(II) bis-isocyanide complexes cis-[PdCl2(CNR)2] (R = 2,6-Me2C6H3, 2-Me-6-ClC6H3) with an equimolar amount of chelating N,O-binucleophiles, 2-aminophenol and (2-aminophenyl)-methanol, in acetonitrile at room temperature in 24 h selectively afforded the corresponding open-chain monocarbene complexes. The complexation involved one isocyanide ligand and amino group of the aromatic amine. Neither bis(carbene) complexes (in the reactions with 4 equiv of the nucleophile under harsh conditions) nor C,O-chelate structures were detected. The isolated complexes were characterized by elemental analyses, IR, NMR, and mass spectra, and X-ray diffraction data.

Phenoxazine compounds produced by the reactions with bovine hemoglobin show antimicrobial activity against non-tuberculosis mycobacteria.

We studied the anti-microbial effects of phenoxazines produced by the reaction of o-aminophenol or its derivatives with bovine hemoglobin, on seven species of mycobacteria such as Mycobacterium tuberculosis, Mycobacterium marinum, Mycobacterium intracellulare, Mycobacterium scrofulaceum, Mycobacterium fortuitum, Mycobacterium kansasii and Mycobacterium smegmatis and some bacteria such as Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica serovar Typhimurium, Staphylococcus aureus, Listeria monocytogeneses. These phenoxazines, including 2-amino-4, 4alpha-dihydro-4alpha, 7-dimethyl-3H-phenoxzine-3-one (Phx-1), 3-amino-1, 4alpha-dihydro-4alpha, 8-dimethyl-2H-phenoxazine-2-one (Phx-2), and 2-aminophenoxazine-3-one (Phx-3), prevented the proliferation of four non-tuberculosis mycobacteria including M. scrofulaceum, M. kansasii, M. marinum, and M. intracellulare dose-dependently, though the inhibitory effects of these phenoxazines differed according to the species of mycobacteria. However these phenoxazines failed to prevent the proliferation of M. tuberculosis, M. fortuitum, and M. smegmatis, and the concerned bacteria other than mycobacteria. The present results may contribute to development of novel antibiotics against non-tuberculolsis mycobacteria.

Carbonylation of o-Phenylenediamine and o-Aminophenol with Dimethyl Carbonate Using Lead Compounds as Catalysts

Lead compounds are active catalysts for carbonylation and carbonylation/methylation of o-phenylenediamine and o-aminophenol with dimethyl carbonate (DMC). 2-Benzimidazolone was obtained in 84% yield by the reaction of o-phenylenediamine with DMC for 1 h at 443 K in the presence of Pb(NO3)2. In the presence of Pb(OAc)2, the reaction quantitatively gave 1,3-dimethyl-2-benzimidazolone, which was formed by methylation of the primary product, 2-benzimidazolone, at 473 K. The effects of reaction variables on the yields of 2-benzimidazolone and 1,3-dimethyl-2-benzimidazolone were examined. The reaction of o-aminophenol with DMC selectively gave a carbonylation product, 2-benzoxazolone, or a carbonylation/methylation product, 3-methyl-2-benzoxazolone, depending on the reaction conditions in the presence of Pb(OAc)2.

REACTIONS OF 4-ISOTHIOCYANATO-4-METHYL-2-PENTANONE WITH AMINES HAVING FUNCTIONAL GROUP AT β POSITION AND ANTI-INFLAMMATORY EVALUATION OF RESULTING HETEROCYCLIC COMPOUNDS

Abstract The reaction of 4-isothiocyanato-4-methyl-2-pentanone with o-phenylenediamine at room temperature yielded isomeric mixture of 1-(2′-aminophenyl)-4,4,6-trimethyl-1,4,5,6-tetrahydro-6-hydroxypyrimidine-2(3H)-thione (I), which on refluxing in MeOH with catalytic amount of sulphuric acid cyclizes to yield the known pyrimidobenzimidazole (IIa). The same product was also obtained by direct condensation of o-phenylenediamine with 4-isothiocyanato-4-methyl-2-pentanone in the presence of catalytic amount of acid and heating under reflux for 8 h. The reaction of 4-nitro-1,2-phenylenediamine with 4isothiocyanato-4-methyl-2-pentanone gave IIb. The reaction of o-aminophenol with 4-isothiocyanato4-methyl-2-pentanone at pH 4.3 gave 1-(2′-hydroxyphenyl)-4,4,6-trimethyl-1,4-dihydro-pyrimidine-2(3H) thione (III), however the same reaction under strongly acidic conditions (pH ∼ 1) gave the known pyrimidobenzoxazole (IV). The reaction of 4-isothiocyanato-4-methyl-2-pentanone with o-aminothiophenol and 2-amino ethanol under different pH conditions gave the known heterocycles V and VI, respectively. The structures of these compounds are supported by IR, 1H NMR and HRMS. Anti-inflammatory evaluation of I, IIa, IIb, III, IV, V and VI at 100 mg/kg showed that compounds I, IIa, III, and IV are inactive whereas, compounds IIb, V and VI showed 13%, 11%, and 21% activity, respectively.

ChemInform Abstract: 2-(o-Hydroxyanilido)alkylnitriles vs. 2-(1-(o-Hydroxyanilido)alkyl)benzoxazoles as Products from o-Aminophenol and Cyanohydrins.

The reaction of o-aminophenol with cyanohydrins leads to the formation of novel benzoxazoles 2 or the expected 2-(o-hydroxyanilido)alkylnitriles 3 or mixtures of these two, depending on the alkyl substituents on the cyanohydrin. The formation of benzoxazoles 2 was found to be due to the intrinsic instability of the corresponding 2-(o-hydroxyanilido)alkylnitriles, such as 4.

ChemInform Abstract: Chemistry of O,N‐ and S,N‐Containing Heterocycles. Part 9. Formation of Pyrido(2,1‐d) (1,5)benzoxazepines and Pyrido(2,1‐d) (1,5)benzothiazepines.

AbstractWhereas the reaction of o‐aminophenol (I) with acetone (II) is reported to yield (III), that of o‐aminothiophenol is reported to give (VIII).

The Synthesis of (3'-Oxo-3',4'-Dihydro-2'h-1',4'-Benzothiazin-2'-Yl)Acetic Acid and (3'-Oxo-3',4'-Dihydro-2'h-1',4'-Benzoxazin-2'-Yl)Acetic Acid-Derivatives

Reaction of o-aminophenol with various maleic anhydrides gave first 2-hydroxymaleanilic acids (4-(2′-hydroxyphenylamino)-4-oxobut-2-enoic acids) (1), which were then converted into the 3-oxo-1,4-benzoxazines (2d-h) and (3f-1) under mild basic conditions; similarly the reaction of o- aminothiophenol with the maleic anhydrides gave the 3-oxo-1,4-benzothiazines (2a), (3a) and (3d) in one step. The facile cycloaddition and esterification of 2-hydroxymaleanilic acids to form the benzoxazines observed in this work is discussed in terms of the formation of the isomaleimide type intermediate (7).

ChemInform Abstract: PHENOXAZINE DERIVATIVES AS PRODUCTS OF THE REACTION OF O‐AMINOPHENOL WITH CHALCONES

The reaction of o-aminophenol with 4- and 4′-substituted chalcones and benzalacetones in methanol (with a tertiary amine as the catalyst), which leads to products of β addition of 2-aminophenoxazin-3-one to the C=C bond of an unsaturated ketone, was investigated. The activating role of the unsaturated ketone in the formation of a phenoxazine fragment was examined. The structures of the synthesized compounds were confirmed by IR, UV, PMR, and mass spectrometry.

Synthesis of the analytical ligand 2-tert.-butyl-8-hydroxyquinoline

Two methods for the synthesis of 2-tert.-butyl-8-hydroxyquinoline are described. One involves a direct reaction of the parent compound with tert.-butyl-lithium, and the other is based on a cyclization reaction of o-aminophenol with 3-chloro-4,4-dimethylpent-2-enal. Physical data confirming the structure of the compound are presented.

Reaction of o-aminophenol with diphenoxytrichloro-phosphorane and pentaphenoxyphosphorane

1. The reaction of o-aminophenol with diphenoxytrichlorophosphorane or pentaphenoxyphosphorane leads to the formation of spirophosphorane (II).

Determination of Copper by Catalysis of the Oxidation Reaction of O-Amino Phenol

Abstract The oxidative dimerization reaction of o-amino phenol with dissolved oxygen is catalyzed by the presence of an extremely small amount of copper(II) ion. In a. c. polarography, the oxidation product of o-amino phenol gives a very sensitive tensammetric wave in the pH range 5 to 9. This tensammetric wave is used for the determination of copper(II) ion from 0.3 to 3.5 μg/100 ml final solution.

Phosphonitrilic compounds. VIII. Reaction of o-aminophenol with phosphazenes

Phosphonitrilic compounds. VIII. Reaction of o-aminophenol with phosphazenes

Aminophenols. I. The Reaction of o-Aminophenol with Chloracetic Acid and Some Comments on the Formation of Phenmorpholones1

Aminophenols. I. The Reaction of o-Aminophenol with Chloracetic Acid and Some Comments on the Formation of Phenmorpholones¹