Acetals methylation

Methyl formate. Ethyl formate Methyl acetate Iso-propyl formate Ethyl acetate Methyl propionate "-Propyl formate Iso-propyl acetate Methyl iso-butyrate Iso-butyl formate. Ethyl propionate M-Propyl acetate. Methyl butyrate. ... 

Successful results have been obtained (Renfrew and Chaney, 1946) with ethyl formate methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec.-butyl and iso-amyl acetat ethyleneglycol diacetate ethyl monochloro- and trichloro-acetates methyl, n-propyl, n-octyl and n-dodecyl propionates ethyl butyrate n-butyl and n-amyl valerates ethyl laurate ethyl lactate ethyl acetoacetate diethyl carbonate dimethyl and diethyl oxalates diethyl malonate diethyl adipate di-n-butyl tartrate ethyl phenylacetate methyl and ethyl benzoates methyl and ethyl salicylates diethyl and di-n-butyl phthalates. The method fails for vinyl acetate, ieri.-butyl acetate, n-octadecyl propionate, ethyl and >i-butyl stearate, phenyl, benzyl- and guaicol-acetate, methyl and ethyl cinnamate, diethyl sulphate and ethyl p-aminobenzoate. 

Methyl 1.2,3,4-tetracarbazole-2-acetate Methyl 4-oxo-l,2,3,4-tetraIlyd o-ca ba2oIe-2-acetate DDQ, THF, HjO 85 [5]... 

An a priori method for choosing a surfactant was attempted by several researchers (50) using the hydroph i1 e—1 ip oph i1 e balance or HLB system (51). In the HLB system a surfactant soluble in oil has a value of 1 and a surfactant soluble in water has a value of 20. Optimum HLB values have been reported for latices made from styrene, vinyl acetate, methyl methacrylate, ethyl acrylate, acrylonitrile, and their copolymers and range from 11 to 18. The HLB system has been criticized as being imprecise (52). 

The nmr spectmm of PVAc iu carbon tetrachloride solution at 110°C shows absorptions at 4.86 5 (pentad) of the methine proton 1.78 5 (triad) of the methylene group and 1.98 5, 1.96 5, and 1.94 5, which are the resonances of the acetate methyls iu isotactic, heterotactic, and syndiotactic triads, respectively. Poly(vinyl acetate) produced by normal free-radical polymerization is completely atactic and noncrystalline. The nmr spectra of ethylene vinyl acetate copolymers have also been obtained (33). The ir spectra of the copolymers of vinyl acetate differ from that of the homopolymer depending on the identity of the comonomers and their proportion. 

Investigation has shown that chain transfer to polymer occurs predominantly on the acetate methyl group in preference to the chain backbone one estimate of the magnitude of the predominance is 40-fold (92,93). The number of branches per molecule of poly(vinyl acetate) polymerised at 60°C is ca 3, at 80% conversion. It rises rapidly thereafter and is ca 15 at 95% conversion and 1-2 x lO" number-average degrees of polymerisation. 

Tetrachloroethylene reacts with formaldehyde and concentrated sulfuric acid at 80°C to form 2,2-dichloropropanoic acid [75-99-0] (8). Copolymers with styrene, vinyl acetate, methyl acrylate, and acrylonitrile are formed in the presence of dibenzoyl peroxide (9,10). 

Modifications of epichlorohydrin elastomers by radical-induced graft polymeri2ation have been reported. Incorporated monomers include styrene and acrylonitrile, styrene, maleic anhydride, vinyl acetate, methyl methacrylate, and vinyHdene chloride (81), acryHc acid (82), and vinyl chloride (81,83,84). When the vinyl chloride-modified epichlorohydrin polymers were used as additives to PVC, impact strength was improved (83,84). 

Acetone with benzene, butyl acetate, butyl alcohol, carbon tetrachloride, chloroform, cyclohexane, ethanol, ethyl acetate, methyl acetate, acetonitrile, petroleum ether or water. 

Isoamyl acetate (banana Vinyl acetate Methyl vinyl acetate Benzyl acetate Cyclohexyl acetate... 

Because the polymer degrades before melting, polyacrylonitrile is commonly formed into fibers via a wet spinning process. The precursor is actually a copolymer of acrylonitrile and other monomer(s) which are added to control the oxidation rate and lower the glass transition temperature of the material. Common copolymers include vinyl acetate, methyl acrylate, methyl methacrylate, acrylic acid, itaconic acid, and methacrylic acid [1,2]. 

Methyl-onn-azoxymethyl acetate (Methyl azoxy methyl acetate)... 

Methyl-l -butene N-Methylbutylamine Methyl butyl ketone Methyl butyrate Methyl cellosolve Methyl cellosolve acetate Methyl chloride... 

Ammonium nitrate and other ammonium salts Any oxidizable substance, such as ethanol, methanol, glacial acetic acid, acetic anhydride, benzaldehyde, carbon disulphide, glycerol, ethylene glycol, ethyl acetate, methyl acetate or furfural Chlorates, perchlorates, permanganates... 

Methyl(/i-amyl)ketone (2-heptanone) 5-Methyl-3-heptanone Methyl acetate Methyl acetylene... 

Methyl ethyl ketone peroxide Methyl formate Methyl iodide Methyl isoamyl acetate Methyl isobutyl carbinol Methyl isobutyl ketone (hexone)... 

Ethylene glycol monomethyl ether acetate (methyl cellosolve acetate)... 

Another internal acetal, methyl 2-0-benzoyl-3,4-0-benzylidene-/ -D-arabinopyranoside 103 (84), behaves in an analogous manner, except that the isomeric 4-bromo (104) and 3-bromo (105) benzoate derivatives are formed in a ratio of 1 1. The identity of 104 (l-xylo) can be deduced from its mode of formation from a presumed benzoxonium ion (106)... 

R+ is intense in methyl acetate, methyl propionate, methyl butyrate, and methyl pentanoate. 

Acetaldehyde, acetone, tetrahydrofuran (THF), ethyl acetate, isopropyl alcohol, ethyl alcohol, 4-methyl-l,3-dioxolane, n-pro-pyl acetate, methyl isobutyl ketone, -propyl alcohol, toluene, n-butyl alcohol, 2-ethoxyethanol, and cyclohexane... 

There is a considerable body of evidence (kinetic studies, chemical and NMR analysis) indicating that transfer to VAc monomer involves largely, if not exclusively, the acetate methyl hydrogen to give radical 111 (Scheme 6.29).171,172 This radical (111) initiates polymerization to yield a reactive macromonomer (112). 

PVAc is known to contain a significant number of long chain branches. Branches to the acetate methyl may arise by copolymerization of the VAe macromonomcr produced as a consequence of transfer to monomer (Section 6.2.6.2). Transfer to polymer may involve either the acetate methyl hydrogens (Scheme 6.34) or the methine (Scheme 6.35) or methylene hydrogens of the polymer backbone. 

The presence of hydrolyzable long chain branches in PVAc was established by McDowell and Kenyon206 in 1940. They observed a reduction in molecular weight obtained on successively hydrolyzing and reacetylating samples of PVAc. Only branches to the acetate methyl will be lost on hydrolysis of the polymer i.e. on conversion of PVAc to PVA. 

The proposal that PVAc also has non-hydrolyzable long chain branches stems from the finding that PVA also possesses long chain branches. No/akura et a/.171 "07 suggested, on the basis of kinetic measurements coupled with chemical analysis, that chain transfer to PVAc involves preferential abstraction of backbone (methine) hydrogens (ca 5 1 v,v the acetate methyl hydrogens at 60 °C). 

Some part of the cellulose fraction is redirected to make cellulose derivatives, such as cellulose acetate, methyl and ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose. These derivatives find multiple applications, for instance, as additives in current products (e.g., paints, lacquers) of chemical industry. Typically, the preparation of cellulose derivatives takes place as a two-phase reaction cellulose is pretreated, for example, with alkali, and a reagent is added to get the substitution. Usually no catalyst is needed [5]. 

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