henols and phenolic substances are aromatic hydroxy compounds classified as monohydric (e.g., phenol, cresols [methylphenols], xylenols [dimethylphenols]), dihydric (e.g., catechols [odihydroxybenzenes], resorcinols [m-dihydroxybenzenes]) or polyhydric (with three or more hydroxy groups), depending on the number of hydroxyl groups attached to the aromatic benzene ring (McNeely et al. 1979). The...

Over 60 lignin-related model compounds were phosphitylated with 2chloro-4,4,5,5-tetramethyldioxaphospholane, a sterically hindered analogue of 2-chloro-1,3,2-dioxaphospholane used in earlier work, and their 31P chemical shifts were recorded. Excellent resolution between the chemical shifts of phosphitylated carboxylic acids, phenols and aliphatic alcohols was obtained. The correlations of the p...

Bark is one of the most under-utilized types of lignocellulosic biomass in the forest industry. In this study, bark fast pyrolysis was optimized for phenols yield using response surface methodology (RSM), considering the pyrolysis temperature, gas flow rate, and biomass particle size. The bio-oil generated under optimal conditions was then characterized by gas chromatography-mass spectrometry (...

3-methyl-1-(4-sulfobuthyl)-1-h-imidazol-3ium hydrogen sulfate, as a dual acidic ionic liquid (dail), was found to be an efficient catalyst for the simple, rapid and green synthesis of substituted trisphenols from the condensation of different substituted phenols and 2,6-bis (methylol) phenols (bmp). dail catalyst efficiently promoted the reaction between phenols and bmps with a variety of funct...

nitration of phenol and various 4-substituted phenols with cu(no3)2.3h2o, cu(no3)2.3h2o/sio2, 9h2o and cr(no3)2. 9h2o in different anhydrous organic solvents are investigated. high selectivity ratio of para vs ortho isomers has been observed. mono- and dinitro compounds from phenol and 4-substituted phenols by choosing the proper solvents and reaction conditions, are also obtained with high sel...

Dry olive mill residue (DOR) from the olive oil production by two phase centrifugation system was fractionated by a consecutive continuous solid-liquid extraction obtaining the EAF, PF, MF and WF fractions with ethyl acetate, n-propanol, methanol and water, respectively. The chemical, chromatographic and mass spectrometric analyses showed EAF, PF and MF to be mainly composed of simple phenols, ...

Total phenols were determined by molecular spectmphotometry, after distillation, complexation with Caminoantipyrine and extraction into chloroform. Cyanides were also determined spectrophotometrically after distillation from the acidified samples, and complexation in moderate acidic solution with barbituric acid. The dynamic ranges were 0 100 pg L-' for total phenols and 0 30 pg L-' for cyanide...

Ubiquitous tyrosinase catalyses the aerobic oxidation of phenols to catechols through the binuclear copper centres. Here, inspired by the Fischer indole synthesis, we report an iridium-catalysed tyrosinase-like approach to catechols, employing an oxyacetamide-directed C-H hydroxylation on phenols. This method achieves one-step, redox-neutral synthesis of catechols with diverse substituent group...

OBJECTIVE To study the correlation of toxicity with biodegradability (BODT) in order to promote QSBR development and understand the degradation mechanism. METHODS Toxicity of substituted phenols to river bacteria was determined by the turbidities that were measured using a spectrophotometer (UV-190) at 530 nm against a blank control. The biodegradability of substituted phenols was expressed a...

The distribution coefficients for phenols (phenol, o-cresol, m-cresol, p-cresol, 3,5-xylenol and α-naphthol) in ionic liquid (1-butyl-3-methylimidazolium haxafluorophosphate ([bmim][PF6]))/water two-phase system were measured at 298 K to examine a removal ability of phenols in wastewater by the liquid-liquid extraction. Judging from these distribution coefficients, it is feasible that phenols c...