Epichlorohydrin heterocycles

Specialty Epoxy Resins. In addition to bisphenol, other polyols such as aliphatic glycols and novolaks are used to produce specialty resins. Epoxy resins may also include compounds based on aliphatic, cycloaliphatic, aromatic, and heterocyclic backbones. Glycidylation of active hydrogen-containing structures with epichlorohydrin and epoxidation of olefins with peracetic acid remain the important commercial procedures for introducing the oxirane group into various precursors of epoxy resins. 

The coordination polymerisation and copolymerisation of heterocyclic monomers have been restricted in industry to a much smaller volume than the polymerisation and copolymerisation of hydrocarbon monomers polyether elastomers from epichlorohydrin and ethylene oxide or propylene oxide, and allyl glycidyl ether as the vulcanisable monomeric unit, are produced on a larger scale [4-7],... 

This is a much more convenient and satisfactory synthesis of 3-hydroxyglutaronitrile than earlier ones. " The method can be applied to other epichlorohydrins 2-methylepichlorohydrin and 2-ethylepichlorohydrin have been converted to the corresponding hydroxydinitriles in 71% and 77% yields, respectively. The hydroxydinitriles undergo cyclizations to heterocyclic compounds not easily prepared in other ways. Thus hydrogen bromide at 0° converts 3-hydroxyglutaronitrile to 2-amino-6-bromopyridine in 70% yield. ... 

An interesting concept for the preparation of seven-membered heterocycles with several heteroatoms was reported in 1988 by Burger and coworkers. Base-catalyzed reaction of hexafluoroacetone imine derivatives 53 with epichlorohydrine resulted in the formation of l,5-dioxa-3-azepines 54 and l-oxa-3,5-diazepines 55 (Fig. 10.24). ... 

Heterocyclic Epoxy Compounds. The technically most important heterocyclic epoxy resin is triglycidyl isocyanurate, obtained by reacting cyanuric acid with epichlorohydrin (Araldite PT 810, Ciba-Geigy Tepic, Nissan). This trifunctional epoxy resin is combined with carboxy-terminated polyesters to give weather-resistant powder coatings [2.122]-[2.124]. 

The monomer is obtained by reacting bisphenol A with epichlorohydrin. Compounds with q = 0.1-0.6 are liquids, those with q = 2-12 are solids. Other epoxide resins are based on epoxidized phenol/formaldehyde and cresol/formaldehyde resins, or on cycloaliphatic or heterocyclic structures. Commercially available epoxide resins are generally compounded, that is, they also contain plasticizers, diluents, pigments, etc. 

Although butyl rubber is by far the most important commercial elastomer to be synthesized by cationic polymerization, several heterocyclic monomers provide useful elastomeric materials via this mechanism also. Epichlorohydrin can be polymerized to high molecular weight using a complex catalyst formed from a trialkylaluminum compound and water as shown in Eq. (58) [64, 130-132], For copolymerizations with ethylene oxide, a catalyst formed from a trialkylaluminum compound, water, and acetylacetone is useful [64,130], The mechanism proposed for these polymerizations is... 

Methylimidazole (EMI) n. An epoxy-resin curing agent with a heterocyclic structure. EMI is used with epoxies formed from epichlorohydrin and bisphenol A or -F, and for novolac epoxy resins. It provides ease of compounding, long pot life, low viscosity, and non-staining characteristics. 

These included polyphenolic compounds, mono and diamines, amino phenols, heterocyclic imides and amides, aliphatic diols and polyols, and dimeric fatty acids. Epoxy resins derived from epichlorohydrin are termeA glycidyl-hased resins. 

Formation of Bi (acyl ilane ). 2-TMS-l,3-dithiane has also been used in the generation of acylsilanes. Recently 1,4-, 1,5-, 1,6-and l,7-bis(acylsilanes) have been reported and used to produce silyl-substituted heterocycles. For example. Bouillon and Portella reported, in 1997, the formation of 1,5- and l,6-bis(acylsilanes) employing 2-lithio-2-TMS-l,3-dithiane and epichlorohydrin and diepoxide, respectively, as electrophiles (eqs 30 and 31). In the latter case the acylsilane was not isolated, as upon treatment with CaCOs and I2 the resulting acylsilane underwent cyclization to furnish the 2,5-bis-trimethylsilylfuran. 

Cyclic ethers are the class of heterocyclic monomers that provide suitable models for mechanistic studies. Polymerization of several monomers of this class leads to polymeric materials that are produced on an industrial scale. The most prominent examples are polymers of ethylene oxide (EO), propylene oxide (PO), epichlorohydrin (ECH), or tetra-hydrofiiran (THE). Cationic ring-opening polymerization (CROP) of cyclic ethers is thus interesting from both an academic and industrial point of view. 

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