Chloromethylated poly reactions

This heterocycle has been appended (76CPB1349) in overall 95% yield based on starting chloromethylated poly(styrene) (192) by utilizing the sequence of reactions shown in Scheme 92. The thiohydarttoin-functional resin (193) was stable in aqueous media below pH 10 and exhibited a high degree of selectivity for Hg2+ ion in competition with Cu2+, Cd2+, Zn2+, Co2+ and Mg + ions. 

The oxazolidine-2,5-dione heterocycle, perhaps better known as the N-carboxyanhydride of an amino acid, has been incorporated employing a modification of chloromethylated poly(styrene) (192) (76USP3985715). The reaction sequence involved utilization of a masked amino acid, ethyl acetamidocyanoacetate (205). The amino acid was liberated in a subsequent hydrolysis/decarboxylation step (Scheme 98). The cyclized, IV-carboxyanhydride-functional resins (206) were reported to be useful in solid phase peptide synthesis and as supports for enzyme immobilization. 

Soluble, amphoteric ion exchange resins have been prepared by reaction of pyridinecarb-oxylic acids, especially 2-pyridinecarboxylic acid (215), with chloromethylated poly(styrene) (192 Scheme 104) (76IZV33). Resin (216) exhibited pronounced selectivity for Cu2+ and Ni2+ ions, and also, at pH 1.65, for the U022 ion. 

The main reactions taking place when chloromethylated polystyrene (CMS) and chloromethylated poly(diphenylsiloxane) (SNR) are irradiated with high energy electrons or deep UV (KrF excimer laser, 248 nm) radiation have been studied. The results are discussed in terms of short-lived reactive species generated using pulse radiolysis and laser (248 nm) photolysis techniques. 

By analogous fashion to imidazoline synthesis (Section 1.11.4.2.2), oxazolines have been introduced by modification of an acrylonitrile-containing polymer with ethanolamine (75JAP(K)75160392). In another modification (Scheme 99), chloromethylated poly(styrene) (192) was treated with a lithiated oxazoline (207) derived from reaction of 2-methyloxazo-line and butyllithium (78MI11106). The oxazoline groups were incorporated, in this study, as intermediates to carboxyl groups. 

Usual attachment of the first amino acid unit to the chloromethylated poly-styrene-divinylbenzene resin has been improved, for example, with Boc-Asn, by-condensing the amino acid (2.0 mmoles) in DMF with triethylamine (1.8 mmoles) during one day at room temperature. Cleavage of the peptide end product from the polymer as the amide derivative has been accomplished using ammonia in DMF in a sealed reaction vessel at room temperature for 5 days. A careful stud - of several peptide bond-forming reagents and polymer supports in respect to racemization has revealed the DCCI procedure to be far inferior to DCCI-NHS or EEDQ. With the model tripeptide Gly-Ala-Leu (racemization assessment by means of the Izumiya procedure), the product was found to... 

Quaternary ammonium ion exchange resins were produced initially by chloromethylating crosslinked polystyrene beads with chloromethyl methyl ether, followed by quaternization with tertiary amines. We have circumvented exposure to the highly carcinogenic bis(chloromethyl) ether, a common contaminant of commercial chloromethyl methyl ether, by employing l,4-bis(chloromethoxy)butane or 1-chloromethoxy-4-chlorobutane and have produced chloromethylated poly(oxy-2,6-dimethyl-1,4-phenylene) and polysulfone. Alternatively, chloromethyl methyl ether can be generated from acetyl chloride and methylal, and the reaction mixture utilized directly in chloromethylation of activated aromatic repeat units. 

Dimroth rearrangement, 5, 438 Imidazolium chloride, 4-chloromethyl-reaction with poly(vinyl alcohol), 1, 306 Imidazolium chloride, 2,4,5-tri(diethylamino)-reduction, 5, 415 Imidazolium complexes, 7, 746... 

An important side reaction is the formation of diaryl methane derivatives ArCHaAr. Moreover poly substituted products may be obtained as minor products. Aromatic compounds have been treated with formaldehyde and hydrogen bromide or hydrogen iodide instead of hydrogen chloride. The formaldehyde may be replaced by another aldehyde the term Blanc reaction however stands for the chloromethylation only. 

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