Butyl cresol purification

Buttner-Rosin pneumatic dryer, 265 performance, 264 Butyl cresol purification, 547... 

Methylphenol. y -Cresol is produced synthetically from toluene. Toluene is chlorinated and the resulting chlorotoluene is hydrolyzed to a mixture of methylphenols. Purification by distillation gives a mixture of 3-methylphenol and 4-methylphenol since they have nearly identical boiling points. Reaction of this mixture with isobutylene under acid catalysis forms 2,6-di-/ f2 -butyl-4-methylphenol and 2,4-di-/ f2 -butyl-5-methylphenol, which can then be separated by fractional distillation and debutylated to give the corresponding 3- and 4-methylphenols. A mixture of 3- and 4-methylphenols is also derived from petroleum cmde and coal tars. 

In the case of low temperature tar, the aqueous Hquor that accompanies the cmde tar contains between 1 and 1.5% by weight of soluble tar acids, eg, phenol, cresols, and dihydroxybenzenes. Both for the sake of economics and effluent purification, it is necessary to recover these, usually by the Lurgi Phenosolvan process based on the selective extraction of the tar acids with butyl or isobutyl acetate. The recovered phenols are separated by fractional distillation into monohydroxybenzenes, mainly phenol and cresols, and dihydroxybenzenes, mainly (9-dihydroxybenzene (catechol), methyl (9-dihydtoxybenzene, (methyl catechol), and y -dihydroxybenzene (resorcinol). The monohydric phenol fraction is added to the cmde tar acids extracted from the tar for further refining, whereas the dihydric phenol fraction is incorporated in wood-preservation creosote or sold to adhesive manufacturers. Naphthalene Oils. Naphthalene is the principal component of coke-oven tats and the only component that can be concentrated to a reasonably high content on primary distillation. Naphthalene oils from coke-oven tars distilled in a modem pipe stiU generally contain 60—65% of naphthalene. They are further upgraded by a number of methods. 

Wang resin was purchased from Advanced ChemTech (1% DVB, 0.70mmol/g substitution, 100-200 mash, Cat. SA5009). Anhydrous tetrahydrofuran (THF), A/A-dimcthyl-formamide (DMF), methanol, dichloromethane, pyridine, 1,1 -carbonyldiimidazole (CDI), piperazine, homopiperazine, trans-1,4-diaminocyclohexane, 4-(dimethylamino)pyridine (DMAP), succinic anhydride, diglycolic anhydride, 3-methyl-glutaric anhydride, 2-aminophenol, 2-amino-p-cresol, 2-amino-4-tert-butyl phenol, /V-methylmorpholine (NMM), triphenylphosphine, diethyl azodicarboxylate (DEAD), and trifluoroacetic acid (TFA) were purchased from Aldrich Chemical Company, Inc. and used without further purification. PyBOP was purchased from Novabiochem. 

Upwardly moving crystals, and leaves through the sidewall filter as residue. The movement of crystals is quite positive and not as dependent on particle size as in some other kinds of purifiers. Data are given in the patent (U.S. Pat. 4,309,878) about purification of 2,6-ditertiary butyl para cresol the harvester was operated at 40-60 rpm and filtration rates of 100 lb/(hr)(sqft) were obtained. Other information supplied directly by E.D. Brennan are that a 24 in. dia unit stands 9 ft high without the mixer and that the following performances have been achieved ... 

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