2,4,6-Tris phenol

To better appreciate why reading the specification definitions is so important, let s consider the following example. Imagine a chemist has discovered a tris-phenolic compound (Figure 5.10) and is particularly excited about its antioxidant activity, which will be useful as a food additive due to the compound s apparent lack of toxicity. 

Convergent construction (Scheme 7.14) began with the treatment of (25, 35)-(-)-l,4-di-O-tosyl-2,3-0-isopropylidene-L-threitol with one half equivalent of 4-fert-butylphenol under basic conditions to yield the mono-O-arylation product (62). Subsequent reaction of the chiral aryl ether 62 with one-half equivalent of dihydroxybenzene 42 63, followed by hydrogenolysis with palladium on charcoal gave the dendron 64. Attempted preparation of the disubstituted phenol 64 via reaction of the tosylate 62 with one third equivalent core 61 resulted in low yields (ca. 26 %). Poor solubility of the tris-phenolic trianion was suggested as a rationale for the low conversion. 

As industrial relevant Friedel-Crafts reaction, the synthesis of Bisphenol-F, a material for epoxy resin, from phenol and formaldehyde was chosen [57]. This reaction involves formation of higher order condensates such as tris-phenols. To minimize the latter, the molar ratio of phenol to formaldehyde is set to a very high value (30-40), which is more than 15 times larger than the amount theoretically necessary. Three types of micromixers were used. These are a T-shaped mixer with 500 pm inner diameter, a multilaminating interdigital micromixer with 40 pm channels and a so-called self-made K-M micromixer with center collision mixing. 

Raymond and co-workers have synthesized and separated optical and geometrical isomers of simple tris hydroxamate chroniium(III) and tris phenolate chromium(III) or rhodium(III) complexes and assigned the absolute configurations of these isomers based on criteria such as chromatographic behavior due to differences in dipole moment, theoretical symmetry considerations, and X-ray crystallographic data 174). The absolute configuration of isomers of chromium(III) complexes of ferrichrome, ferrichrysin 175), ferrioxamine B and Dx 176), rhodotorulic acid 177), enterobactin 178),... 

Figure 17 Examples of amine bis- and tris(phenolate)-ligand-based catalysts for lactide ROP...

According to a patent of the Sumitomo Co. (1965), tris-phenol phosphate is prepared from phenol by esterification with phosphorus oxychloride, which is then chlorinated, yielding after hydrolysis a chlorophenol mixture with an ortho para ratio of 8 1. Using sulfuryl chloride (SO2CI2) as chlorinating agent, a chlorophenol mixture of ortho para ratio 4.1 5.7 is formed in the presence of Lewis acid catalysts. 

The linear bi- and tri-phenolic oligomers formed in the condensation of p-tert-butylphenol and formaldehyde i.e. the precursors to calixarenes) have been shown to form intermolecular associated dimers even at concentrations lower than 10 These have been called hemicalixarenes (see ref. 1, pp. 53-54) and presumably play a significant role in the proclivity of the linear oligomers to form cyclic oligomers. 

Another proof for incorporation of the originally present antioxidant into an oxidized polypropylene was provided by 14C-labelled Ionox 330. The structures XC and LXXXV (R = polypropylene residue) were proposed for the reaction product123. It is, however, more probable that the transformation products of tris-phenolic antioxidant are bonded to the polypropylene skeleton in a simpler way for steric reasons than under formation of a polymer network. 

The product, arbutin, was identified by chromatographic and colorimetric methods. A large variety of di- and tri-phenols (but no monophenols) could substitute for hydroquinones as acceptors in the purified-enzyme system presumably, the enzymes using monophenols as substrates had been lost during purification. 

Figure 8.4 Preparation of Davidson s highly active Ca-amine tris(phenolate). ...

Tris (hydroxymethyl) propane 1,1,1-Tris (hydroxymethyl) propane. See Trimethylolpropane 1,1,3-Tris (hydroxyphenyl) propane Synonyms Tri phenol P Empirical C21H20O3 Formula (C6H40H)2CHCH2CH2C6H40H Properties Wh. solid dens. 1.226 (20/20 C) f.p. 90-110 C, sets to glass below 90-110 C Precaution Combustible Uses Antioxidant, intermediate for polyester and alkyd resins... 

The elements of the 4b transition group were also stabilized by triflates. Titanium is among the most moisture-sensitive elements. Air- and moisture-stable titanium(IV) triflates were prepared by its co-complexation with organic ligands. Reported examples referred to Cj-symmetric amine tris(phenolate) [36] or Binol ligands [37]. These compounds demonstrated efficiency as Lewis acid catalysts for formal a a-Diels-Alder (Equation (8.15)) and the homoaldol (the addition of silyloxycyclopropanes to aldehydes) (Equation (8.16)) reactions. 

The above is a general procedure for preparing trialkyl orthophosphates. Similar yields are obtained for trimethyl phosphate, b.p. 62°/5 mm. triethyl phosphate, b.p. 75-5°/5 mm. tri-n-propyl phosphate, b.p. 107-5°/5 mm. tri-Mo-propyl phosphate, b.p. 83-5°/5 mm. tri-wo-butyl phosphate, b.p. 117°/5-5 mm. and tri- -amyl phosphate, b.p. 167-5°/5 mm. The alkyl phosphates are excellent alkylating agents for primary aromatic amines (see Section IV,41) they can also be ua for alkylating phenols (compare Sections IV,104-105). Trimethyl phosphate also finds application as a methylating agent for aliphatie alcohols (compare Section 111,58). 

Acetates. The acetates of monohydric phenols are usually liquids, but those of di and tri-hydric phenols and also of many substituted phenols are frequently crystaUine sohds. They may be prepared with acetic anhydride as detailed under Amines, Section IV,100,7. 

The reaction is particularly facile with di- and tri-hydric phenols. Thus P-resorcyllc acid is readily obtained by passing carbon dioxide through a boiling aqueous solution of the potassium or sodium salt of resorcinol ... 

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