Phenyl glycidyl ether reaction

Thymidine and 2 -deoxyadenosine react with phenyl glycidyl ether in vitro. The main adducts are A-3-(2-hydroxy-3-phenoxypropyl)thymidine and Wl-(2-hydroxy-3-phenoxypropyl)-2 -deoxyadenosine, respectively. With longer reaction times, a small amount of dialkylated 2 -deoxyadenosine was also formed (Van den Eeckhout et al., 1990). 

The phase transfer catalyzed alkylation reaction of dodecyl phenyl glycidyl ether (DPGE) with hydroxyethyl cellulose (HEC) was studied as a mechanistic model for the general PTC reaction with cellulose ethers. In this way, the most effective phase transfer catalysts and optimum reaction concentrations could be identified. As a model cellulose ether, CELLOSIZE HEC11 was chosen, and the phase transfer catalysts chosen for evaluation were aqueous solutions of choline hydroxide, tetramethyl-, tetrabutyl-, tetrahexyl-, and benzyltrimethylammonium hydroxides. The molar A/HEC ratio (molar ratio of alkali to HEC) used was 0.50, the diluent to HEC (D/HEC) weight ratio was 7.4, and the reaction diluent was aqueous /-butyl alcohol. Because some of the quaternary ammonium hydroxide charges would be accompanied by large additions of water, the initial water content of the diluent was adjusted so that the final diluent composition would be about 14.4% water in /-butyl alcohol. The results of these experiments are summarized in Table 2. 

The increase in alkylation efficiency of HEC with quaternary ammonium hydroxide is not limited to DPGE. Experiments were conducted in which HEC was alkylated with 1-bromohexadecane (cetyl bromide), 3-n-pentadecenyl phenyl glycidyl ether (PDPGE)14, or 1,2-epoxyhexadecane (C]6 a-olefin epoxide) in the presence of either sodium hydroxide or benzyltrimethylammonium hydroxide. As before, the molar A/HEC ratio was 0.50, and the water content of the diluent in the benzyltrimethylammonium hydroxide experiment was decreased to compensate for the higher water content of the base so that the final water content of both reactions was the same (14.4%). The hexadecyl content of the polymers was measured by gas chromatography. The sodium hydroxide mediated reaction of 1-bromohexadecane yielded a hexadecyl alkylation efficiency of 0.5%, while the benzyltrimethylammonium hydroxide reaction yielded a hexadecyl alkylation efficiency of 6.2%. A twelve-fold increase in the hexadecyl alkylation efficiency was observed in the reaction conducted with the quaternary ammonium hydroxide. 

Matejka et al. 51> studied the reaction of phenyl glycidyl ether (PGE) with acetic or benzoic acid anhydride in the presence of benzyldimethylamine and also with benzoic acid as a co-catalyst. They found that the tert-amine is bound irreversibly through the formation of a quartemary ammonium salt as shown below. 

These compounds can initiate anionic polymerisation of epoxides, and when R, = H the secondary amine can react by addition to an epoxide group. Farkas and Strohm 64> have studied the reaction of 2-ethyl-4-methyl imidazole with phenyl glycidyl ether and BADGE resin using chemical analysis and proton NMR spectroscopy. They found that the imidazole readily forms adducts with epoxide of 1 1 and 1 2 molecular ratio ... 

More recently Bradley and co-workers288 demonstrated a fourth significant product in this reaction to be l,3-dichloro-2-propanol. formed by addition of hydrochloric acid to epiehlorohydrin. These authors then showed that under suitable conditions phenyl glycidyl ether can be mode to react wjth a chlorohydrin. There are formed in this manner a new epoxide and l-chloro-D-phenoxy-2-propanol, ah... 

PhCH2=Ru(PCy3)2Cl2 catalyses the cyclooligomerization of trienes (143) to benzene derivatives (144) via a cascade of four metathesis reactions (Scheme 54).273 Isocyanate cyclotrimerization catalysed by dimethylbenzylamme-phenyl glycidyl ether-phenol has been studied by IR and PMR spectroscopy.274... 

Figure 5.3 Reaction mechanism of the strictly alternating copolymerization of phenyl glycidyl ether (PGE, 2) and phthalic anhydride (PA, 3) initiated by imidazoles (la-c). (Leukel et al., 1996. Copyright 2001. Reprinted by permission ofWiley-VCH)...

The use of model compounds is a convenient starting point to determine the reaction path, particularly for stepwise polymerizations. For epoxy-amine systems, a monofunctional epoxide such as phenyl glycidyl ether (PGE) is often used for these studies (Verchere et al., 1990 Mijovic and Wijaya, 1994). Figure 5.10 shows the reaction scheme for the curing of a monoepoxide with a diamine. 

The reaction of epoxide resins with dicyanates was investigated using a model system. The system consisted of phenyl glycidyl ether and cumylphenyl cyanate [67]. Three reactions proceeded in the system ... 

The />,/> -diamino azobenzene (DAA) reactivity probe, described in the previous section, has been demonstrated to form reaction products with DGEBA-based epoxy resins that have a greater fluorescence intensity than does DAA itself. By examining model adducts with phenyl glycidyl ether, the intensity enhancement varied from 1400 times to 9 times depending on whether the DAA reacted at a crosslink or a chain end, respectively... 

Base-catalyzed anhydride-epoxide reactions have been found to have greater selectivity toward diester formation. Shechter and Wynstra (8) showed that equal molar amounts of acetic anhydride and phenyl glycidyl ether with either potassium acetate or tertiary amines as a catalyst reacted very selectively. They proposed the following reaction mechanism for the acetate ion catalyzed reaction ... 

Figure 4. Reaction of 1.25 mol of phenyl glycidyl ether with 1.00 mol of caprylic acid plus 0.20% (by weight) of KOH catalyst.

Figure 5. Noncatalyzed reaction of equimolar amounts of phenol and phenyl glycidyl ether.

For example, in experiments with phenyl glycidyl ether and isopropyl alcohol (1 1 molar ratio) in which potassium hydroxide and benzyldimethylamine were used as catalysts, Shechter and Wynstra (8) found that after nearly complete consumption of the epoxide group approximately 80% of the charged alcohol was unreacted. This result indicates that the reaction was largely self-polymerization. 

Non-crosslinked polystyrene with salen ligand Non-crosslinked polystyrene with onium salt residues Non-crosslinked polystyrene copolymerised with a chiral phosphine ligand 14,765 0.5-3.8" 0.7-2.3 CH2Cl2,THF, EtOAc, DMF DMF,DMSO,DMA, toluene, anisole, MeOH,MeCN, diglyme Asymmetric epoxidation Regioselective addition reaction of phenyl glycidyl ether with S-phenyl thioacetate Pt-catalysed asymmetric hydroformylation of olefins Precipitation (methanol) (r) Precipitation (diethyl ether) (r) [68] [142] [143]... 

Xu, L. Fu, J.H. Schlup, J.R. (19%). In situ near-infrared spectroscopic investi tion of the kinetics and mechanisms of reactions between phenyl glycidyl ether (PGE) and... 

Alinear-chained epoxy resin was formulated from phenyl glycidyl ether and nadic methyl anhydride catalysed by benzyldimethylamine. Intermolecular polymerisations were modelled as a parallel set of propagation reactions. FTIR spectroscopy was used to determine the concentrations of the oxirane, anhydride and ester moieties within the resin as a function of time for two isothermal cures. Data analyses yielded the propagation rate constant as a function of temp, and the concentration of initiator, including contributions fl om impurities within the resin. Results obtained compared favourably with measurements on fractionated resins, using GPC. Population density distributions are described by Poisson molar distributions for this resin. 25 refs. 

This is in direct contrast to the ineffective reaction of phenyl glycidyl ether with alcohol (4) ... 

Six epoxy-resin-exposed workers from a ski factory showed allergic reactions to the standard DGEBA epoxy resin with the TRUE-Test and Finn Chamber techniques as well as to the epoxy resin used in the factory (Jolanki et al. 1996). Three of the workers reacted to reactive diluents (diethylene glycol dig-lycidyl ether (DEGDGE) (Fig. 1), phenyl glycidyl ether (PGE) and 1,4-butanediol diglycidyl ether (BDDGE). 

Pig. 9. Effect of temperature on the reaction rate as a function of time for photopolymerizations of phenyl glycidyl ether initiated using 8.86 mM of iodonium tetrakis pentafluo-... 

Shechter and Wynstra were the first to examine the uncatalyzed epoxy-phenol reaction." They found that no reaction occurred when equimolar quantities of phenol and phenyl glycidyl ether (PGE, a low molecular weight epoxy) were held at 100 C. When held at 200°C, however, epoxide disappeared at a much faster rate than the phenol, with the net result that about 60% of the reaction was epoxide with phenol (Rxn. 1) and 40% was epoxide with secondary hydroxyl (Rxn. 2). The extent of the second reaction is particularly significant when one considers that the secondary hydroxyl concentration was originally zero and became finite only when some epoxide had reacted with phenol. 

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