Chloromethyl styrene

To illustrate the specific operations involved, the scheme below shows the first steps and the final detachment reaction of a peptide synthesis starting from the carboxyl terminal. N-Boc-glycine is attached to chloromethylated styrene-divinylbenzene copolymer resin. This polymer swells in organic solvents but is completely insoluble. ) Treatment with HCl in acetic acid removes the fert-butoxycarbonyl (Boc) group as isobutene and carbon dioxide. The resulting amine hydrochloride is neutralized with triethylamine in DMF. 

Polypeptide Synthesis and Analysis. Sihca or controUed-pore glass supports treated with (chloromethyl)phenylethyltrimethoxysilane [68128-25-6] or its derivatives are replacing chloromethylated styrene—divinylbenzene (Merrifield resin) as supports in polypeptide synthesis. The sdylated support reacts with the triethyl ammonium salt of a protected amino acid. Once the initial amino acid residue has been coupled to the support, a variety of peptide synthesis methods can be used (34). At the completion of synthesis, the anchored peptide is separated from the support with hydrogen bromide in acetic acid (see Protein engineering Proteins). 

The starting material for the synthesis of this chelating resin is chloromethylated styrene-divinylbenzene, which undergoes an amination reaction and is then treated with monochloracetic acid ... 

Polystyrene-g-poly(ethylene oxide) was synthesized by the copolymerization of styrene and styrenic PEO with CpTiCb/MAO catalyst [190]. In this case the macromonomer was prepared by first reacting the sodium salt of PEO-OH with NaH and then with a 5-fold amount of p-chloromethyl styrene. 

Initial solid phase synthesis25 was carried out on Merrifield s resin (1 % crosslinked chloromethylated styrene/divinylbenzene copolymer, 200-400 mesh) because of its track record in solid-phase peptide synthesis.26 Unfortunately, the Merrifield resin has limitations as a carbohydrate carrier to study interactions between the carbohydrates and relevant binding proteins. The hydrophobic nature of the resin leads to nonspecific, irreversible protein adsorption.27 Later work utilized Rapp s TentaGel, an amphiphilic, polyethylene glycol resin.28... 

Three main types of polymer-based monoliths are polymethacrylate-based monoliths where methacrylate forms the major component of the monomers for polymerization, polyacrylamide-based monoliths where cross-linked polyacrylamide is synthesized directly within the capillary, and polystyrene-based monoliths that are usually prepared from styrene and 4-(chloromethyl) styrene as monomers and divinylbenzene (DVB) as the cross-linker. 

Scheme 4 Hyperbranced multigeneration graft architecture based on sequential repeating process of copolymerization with chloromethyl styrene (CMS) as a comonomer and subsequent dithiocarbamation...

Fig. 9 Top Rose-bengal-stained fluorescence images of photograft-polymerized regions of Models Ay B and C as a function of photopolymerization time or copolymer composition of CMS (see Fig. 8 legend). These indicate that stem-chain length (Model A), daughter-chain length (Model B) and daughter-chain density (Model C) are well-controlled. Bottom Change in fluorescence intensity as a fimction of photopolymerization time or copolymer composition of CMS CMS Chloromethyl styrene...

Accordingly, the synthesis of novel cinnamate polymers with high functionality and performance is very important from the viewpoint of both polymer chemistry and practical use. Recently, we have reported the synthesis of polymers with pendant photosensitive moieties such as cinnamic ester and suitable photosensitizer groups by radical copolymerizations of 2-(cinnamoyloxy) ethyl methacrylate with photosensitizer monomers (9), by copolymerizations of chloromethylated styrene with the photosensitizer monomers followed by the reactions of the copolymers with salts of... 

The fact that allyltributyltin and styrene which are electroneutral were successfully added to PCTFE led us to the question "Can electron-rich or electron-poor trapping agents be used ". The electron-rich agents that we examined were ethyl ethynyl ether and ethyl vinyl ether. On the side of the electron-poor alkenes, eight were investigated ethyl acrylate, methyl methacrylate, methyl vinyl ketone, acrylonitrile, methacrylonitrile, vinyl bromide, chloromethyl styrene, and 4-vinylpyridine. The details of each reaction are summarized. 

In the case of the electron poor alkenes, results were more varied. Under all conditions examined, reactions with methyl vinyl ketone, acrylonitrile, methacrylonitrile and 4-vinyl pyridine afforded products with IR spectra equivalent to those obtained without the addition of the alkene (side reaction). In the cases of vinyl bromide and chloromethyl styrene, unreacted PCTFE was recovered unchanged. It is speculated that electron transfer to the alkene proceeded in each case. While the product of vinyl bromide reduction was not observed, perhaps because of volatility, one could isolate poly(chloromethylstyrene) in the latter case. 

Complex 2 also proved valuable in attaching the ferrocene unit to chloromethylated polystyrene. Treatment of chloromethylated styrene (18% of the phenyl rings modified) with 2 under basic conditions afforded polymer 6. Polymer 7 was then prepared and found to have UV-Vis spectroscopic data analogous to monomer 4 and polymer 5. 

Diffiuex investigated a synthesis of cyclic poly(vinyl ether) using cationic polymerization [26,28]. The reaction process is depicted in Fig. 9. They studied on the living cationic polymerization of 2-chloroethyl vinyl ether (CEVE) initiated with the HI adduct of 4-(vinylbenzyloxy)butyl vinyl ether prepared by reacting chloromethyl styrene with sodium salt of 4-hydroxy-butyl vinyl ether in THF at 80 °C. By the cationic polymerization of CEVE, o /o-hetcrofunclional linear polymer precursor of cyclic poly(CEVE) was produced. The MWDs of the polymers were unimodal and very narrow (< 1.2),... 

The solid support is a special polystyrene bead in which some of the aromatic rings have chloromethyl groups. This polymer, often called the Merrifield resin, is made by copolymerizing styrene with a few percent of p-(chloromethyl)styrene. 

In view of the fact that benzylic cations are responsible for the initiation, graft copolymerization is feasible when the polymer supported pyridinium salts are employed. Endo and co-workers [41] prepared vinyl monomers having pyridinium salt structure. In this case, p-chloromethyl styrene was used as the benzyl halide and the general synthetic strategy was followed. The polymerizable salt was then homo and copolymerized with styrene (Scheme 7). 

AA acac alt AIBN Ar Bd Bu BuA BuMA BzMA CMSty CR CT CTFE DBP DPn EA HEA HEMA HFP acrylamide acetylacetonate alternating azobisisobutyronitrile aromatic group butadiene n-butyl n-butyl acrylate n-butyl methacrylate benzyl methacrylate chloromethyl styrene counter-radical transfer constant chlorotrifluoroethylene dibenzoyl peroxide average degree of polymerization in number ethyl acrylate 2-hydroxyethyl acrylate 2-hydroxyethyl methacrylate hexafluoropropene... 

The hydroxy-tempo derivative 11 is first reacted with p-chloromethyl styrene to give a Tempo capped polymerizable styrenic compound 12. Copolymerization of 12 with styrene gives the multifunctional initiator 13, which has a PS backbone with attached Tempo groups. Reaction of 13 with styrene at 130 °C gives the grafted copolymer 14. After cleavage of the benzyl ether bonds, a Mn of 23000 is determined with a Mw/Mn value of 1.20. 

S6-/>-vinyl-benzylether OH-20S6 + /i-chloromethyl-styrene... 

Anchoring polymers are prepared from chloromethylated styrene-divinylbenzene copolymers of either 1 equiv Cl/g or 4 equiv Cl/g capacity. These resins arc stirred for 24 h in refluxing CHC13, with either 1,4-diazabicyclo[2.2.2]octane, hexamethylenetetramine, or TMEDA. The polymers are filtered off, washed with ClIClj, acetone and Et20, then dried overnight under vacuum at 25 °C. Nitrogen elemental analysis and chloride ion titration gives a value of 80-90% quaternarization. 

The relationship between structure and photoinitiation activity has been examined for polymeric systems bearing side-chain 1-substituted cyclohexyl-phenyl ketone moieties in the UV curing of the HDDA/BA equimolar mixture [19,20]. Indeed, the activity of poly[(l-acryloxycyclohexyl)phenyl ketone] [poly (APK)] and styrene/4-chloromethyl-styrene/l-(4-styrylmethyloxy)cyclohexyl phenyl ketone copolymers (PABOK) has been compared with that of the corresponding low-molecular-weight structural models such as 1-hydroxy-cyclohexyl phenyl ketone (HPK), 1-acetoxy-cyclohexyl phenyl ketone (ACPK) and l-(4-isopropyl-benzyloxy) cyclohexyl phenyl ketone (PIBOK). 

It is therefore concluded that the electronic nature of the substituent in the 1-position of the cyclohexyl ring plays an important role for the activation of this class of photoinitiators, similarly to what is found for benzoin derivatives [4,85]. However, as the photoreactive 4-chloromethylstyrene (CMS) co-units are present in PABOK, the activity of the corresponding PIBOK/poly[(4-chloromethyl)styrene]... 

Polymerization conditions see Table 1 Molar % concentration in the HDDA/BA mixture CMS = 4-chloromethyl styrene units PCMS = poly[(4-chloromethyl)styrene] Determined by IR spectroscopy... 

Luo Q, Wei Y, Liu T, Lei G, and Geng X. Poly(chloromethyl) styrene-co-divinylbenzene continuous rod column of weak cation exchange chromatography and its applications in the separation of biopolymers. Chin. Chem. Lett. 1999 10 215-218. 

Summary AIBN-type radical polymerization initiators have been grafted onto poly-ciystalline titanium surfaces allowing synthesis of polymer films covalently bound to the surfaces. Vinylic monomers such as styrene, methyl methacrylate, and 4-chloromethyl-styrene have been used the pendant benzyl chloride moiety present at the outer surface of the polymer film obtained fi om the latter monomer has allowed further functionalization of the system. In the case of polystyrene films on Ti, molecular weights of the polymer have been estimated to be A/w == 25 000 A/ = 10 000 (Pd = 2.5). 

In the next step, we carried out the polymerization experiments using three vinylic monomers, i.e. styrene, methyl methacrylate, and 4-chloromethyl-styrene, by dipping the appropriate titanium plates into deoxygenated monomer/toluene solutions (1 2, v/v) at 90 °C for 24 h. Interestingly, grafted initiators ACTP and ACTU gave very comparable polymer films from the two styrene monomers, whereas polymerization of methyl methacrylate was found to be significantly better on Ti-ACTP than on Ti-ACTU. 

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