Cresols dimethyl phenols

Bennett and Larter (1997) also studied the solvation of alkylphenols in crude oil-water systems at equilibrium to obtain partitioning coefficients under variable temperature, pressure, and water salinity concentration. Alkylphenol depletion from crude oil, expressed by phenol, cresols, and 3,5 dimethyl phenol, versus temperature in a range of 25-125°C, is given in terms of partition coefficient (P) values (Fig. 16.22). Partition coefficient values increase with addition of alkyl groups to the phenol nucleus. Note that the alkylphenol partition coefficient curves for different isomers tend to converge at higher temperatures and, as a consequence, differences between phenol and p-cresol decrease with increases in temperature. Similar results for oil-deionised water and oil-brine experiments show that increasing temperature leads to a decrease in partition coefficient values. 

Phenol, Dimethyl Xylenols Phenol, Methyl Cresols Methyl Phenol Nickel... 

SYNS 2,5-DiMETHYLPHENOL 3,6-DIMETHYL-PHENOL 2,5-DMP 6-METHYL-m-CRESOL p-XYLENOL 1,2,5-XYLENOL... 

Cresols are an isomeric mixture of the simplest of alkyl phenols, i.e., monomethyl phenol or monohydroxy-toluenes. Similarly xylenols are the next higher homologues of cresols and are known as dimethyl phenols or hydroxy xylenes. 

For electronic applications, 4-hydroxymethyl-3,5-dibromo-2,6-dimethyl-phenol was reacted with cresol novolac to form the m-bromo phenol containing cresol novolac which is then epoxidized to the corresponding epoxy resin (12V. 

Synonyms 2,5-Dimethylphenol 3,6-Dimethyl phenol 2,5-DMP 6-Methyl-m-cresol ... 

Under the same conditions the even more reactive compounds 1,6-dimethylnaphthalene, phenol, and wt-cresol were nitrated very rapidly by an autocatalytic process [nitrous acid being generated in the way already discussed ( 4.3.3)]. However, by adding urea to the solutions the autocatalytic reaction could be suppressed, and 1,6-dimethyl-naphthalene and phenol were found to be nitrated about 700 times faster than benzene. Again, the barrier of the encounter rate of reaction with nitronium ions was broken, and the occurrence of nitration by the special mechanism, via nitrosation, demonstrated. 

Alkylated phenol derivatives are used as raw materials for the production of resins, novolaks (alcohol-soluble resins of the phenol—formaldehyde type), herbicides, insecticides, antioxidants, and other chemicals. The synthesis of 2,6-xylenol [576-26-1] h.a.s become commercially important since PPO resin, poly(2,6-dimethyl phenylene oxide), an engineering thermoplastic, was developed (114,115). The demand for (9-cresol and 2,6-xylenol (2,6-dimethylphenol) increased further in the 1980s along with the growing use of epoxy cresol novolak (ECN) in the electronics industries and poly(phenylene ether) resin in the automobile industries. The ECN is derived from o-cresol, and poly(phenylene ether) resin is derived from 2,6-xylenol. 

O-Alkylation of phenols Phenol/cresols/catechols, alkyl halides/dimethyl sulphate/diethyl sulphate... 

Cresol red Crystal Violet Malachite Green Methanil Yellow Thymol Blue Orange IV -2,4-Dinitrophenol -Erythrosin, Na2 salt -Dimethyl Yellow Cl 11020 Bromophenol Blue Congo Red Cl 22120 Methyl Orange Bromocresol Green Alizarin Red S Cl 42750 Methyl Red Cl 13020 -Bromocresol Purple Chlorophenol Red p-Nitrophenol Alizarin Bromothymol Blue Brillant Yellow Phenol Red Neutral Red Cl 50040 -m-NItrophenol -Cresol Red Metacresol Purple Phenolphthalein -Thymolphthalein -P-Naphthyl Violet Alizarin Yellow R 2,4,6-T rinitrotoluene... 

Kaneda et al. synthesized [61] a series of high molecular weight extended chain copolyimides (XV) by the reaction of PMDA and 3,3, 4,4 -biphenyltetra-carboxylic dianhydride (PPDA) with 3,3 -dimethyl-4,4 -diaminobiphenyl. Solvents used for the one-step synthesis to the fully cyclized imide structure were phenol, p-chlorophenol, m-cresol, p-cresol and 2,4-dicholorophenol. The polycondensations were performed at 180°C for 2h with a monomer concentration of 6% by weight and p-hydroxybenzoic acid used as a catalytic accelerator. A maximum of 50 mol % of PMDA could be used before the copolymer precipitated from solution. Reconstituted copolymers as isotropic dopes (8-10% by weight) in p-chlorophenol were dry-jet wet spun between 80 and 100 °C [62]. 

A special type of polymeric antioxidant is anoxomer, which consists of 1,4-benzenediol, 2-(l,l-dimethylethyl)-polymer with diethylbenzene, 4-(l,l-dimethyl-ethyl)phenol, 4-methoxy-phenol, 4,4 -(l-methylethylidene)bis(phenol), and 4-methylphenol prepared by condensation polymerization of divinylbenzene (m- and p-) with tert-butylhydroquinone, tert-butylphenol, hy-droxyanisole, p-cresol, and 4,4 -isopropylidenediphenol. Total monomers, dimers, and trimers below 500 are not more than 1%. Anoxomer is permitted in the United States as an antioxidant in food at a level of not more than 5 ppm of fat and oil content of the food. 

VNS in recent years has become a valuable and in many instances powerful method for the regiospecific functionalisation of aromatic and heteroaromatic compounds. In a recent study, for example, it was shown that aluminium chloride-catalysed phenylsulfinylation of p-cresol followed by treatment of the product with (a) thionyl chloride, or (b) acetic anhydride/sodium acetate, or (c) p-cresol and TFAA gave, respectively, (a) 2-chloro-4-methyl-6-(phenylthio)phenol, or (b) 2-acetoxy-4-methyl-6-(phenylthio)phenol, or (c) 2,2 -dihydroxy-5,5 -dimethyl-3-(phenylthio)biphenyl. Yields varied from moderate to good (30-78%). 

Thiobis[2-(2-tert-butyl-m-cresol) Phenol, 4,4 -thiobis[2-(1,1 -dimethyl-ethyl)-3-methyl- (4120-97-2), 76, 201, 202... 

Although coal tar is still an industrial source of phenol and the three cresols (methylphenols), e.g. m-cresol (2), and the dimethyl derivatives (xylenols), synthetically manufactured material predominates. 

Pyrolysis of 4-ethylguaiacol yielded 4-ethylphenoI by cleavage of the O-C (alkyl) and O-C (aryl) bonds . Similarly, methyl-, dimethyl- and vinylphenols originated from guaiacol intermediates. It has also been reported that phenol is a secondary pyrolysis product of guaiacol and derivatives. Phenol, cresol, ethylphenol, dimethylphenol, propytphenol and methylcatechol were the main components of the oil fraction in the fourth step. Traces of hydrocarbons such as toluene and styrene were produced by the dehydroxylation of phenols in this fraction. 

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