Methyl acetate, vinylation with methanol

This report describes a process to produce vinyl acetate with high selectivity from exclusively methanol, carbon monoxide, and hydrogen. The simplest scheme for this process involves esterifying acetic acid with methanol, converting the methyl acetate with syn gas directly to ethylidene diacetate and acetic acid, and finally, thermal elimination of acetic acid. Produced acetic acid is recycled. Each step proceeds in high conversion and selectivity. 

Resa, J. M. Gonzalez, C. Moradillo, B. Ruiz, A. Isobaric vapor-liquid equihbria of 3-methyl-1-butanol with methanol and vinyl acetate at 101.3 kPa. Fluid Phase Equilib. 1997, 132, 205-213. 

An industrial example of acidolysis is the reaction of poly(vinyl acetate) with butyric acid to form polylvinyl butyrate). Often a butyric acid-methanol mixture is used and methyl acetate is obtained as a coproduct. 

The free radical polymerization of DADMAC (M,) with vinyl acetate (M2) in methanol proceeds as a nonideal and nonazeotropic copolymerization with monomer reactivity ratios rx=1.95 and r2=0.35 were obtained [75]. The resulting low molar mass copolymers were reported to be water soluble over their whole range of composition. Modification of the vinyl acetate unit by hydrolysis, ace-talization, and acylation resulted in DADMAC products with changed hydrophilic or polyelectrolyte properties [75]. For the copolymerization of DADMAC and AT-methyl-AT-vinylacetamide (NMVA) a nearly ideal copolymerization behavior could be identified [45]. The application properties of the various copolymer products will be discussed in Sect. 8. 

In the second major use of VAM, PVA is converted to poly(vinyl alcohol) (PVOH) by a transesterification reaction with methanol, giving methyl acetate as coproduct. PVOH finds its major end use in textile sizing and adhesives. Further reaction of PVOH with butyraldehyde or formaldehyde gives polyvinyl butyral (PVB) or polyvinyl formal, which together constitute the third largest consumption of VAM. PVB is used almost exclusively in the adhesive laminating inner layer in safety glass. 

Diphenyl carbonate from dimethyl carbonate and phenol Dibutyl phthalate from butanol and phthalic acid Ethyl acetate from ethanol and butyl acetate Recovery of acetic acid and methanol from methyl acetate by-product of vinyl acetate production Nylon 6,6 prepolymer from adipic acid and hexamethylenediamine MTBE from isobutene and methanol TAME from pentenes and methanol Separation of close boiling 3- and 4-picoline by complexation with organic acids Separation of close-boiling meta and para xylenes by formation of tert-butyl meta-xyxlene Cumene from propylene and benzene General process for the alkylation of aromatics with olefins Production of specific higher and lower alkenes from butenes... 

Vinylation of Methyl Acetate and Methyl Propionate with Methanol Over Ti -TSM°... 

Ueda et al. (37) have proposed magnesium oxide catalyst modified with a transition metal ion (M/MgO) for the vinylation of methyl propionate and acetonitrile. Acetonitrile is vinylated to acrylonitrile selectively (94% selectivity at about 10% conversion) over Cr/MgO catalysts at 350 C in the absence of oxygen. The selectivity for the vinylation of methyl propionate over Mn/MgO catalysts is not different from the value obtained with Ti -TSM in the presence of oxygen. The catalyst system, however, is not effective for the reaction of acetic acid. We conducted the reaction of acetonitrile and methanol over Ti -TSM in the presence of oxygen, and found that the vinylation does not take place but the hydrolysis to acetic acid and subsequent esterification with methanol into methyl acetate proceed preferentially. It is likely that Ti -TSM is an appropriate catalyst for the vinylation of carbonyl compounds and M/MgO is appropriate for the vinylation of nitriles. 

Most Williamson reactions proceed by the 8 2 mechanism, but there is evidence (see p. 446) that in some cases the SET mechanism can take place, especially with alkyl iodides. Secondary alcohols have been converted to the corresponding methyl ether by reaction with methanol in the presence of ferric nitrate nonahy-drate. Vinyl ethers have been formed by coupling tetravinyl tin with phenols, in the presence of cupric acetate and oxygen. " The palladium-catalyzed coupling of vinyl triflates and phenols has also been reported. ... 

This oxidation can also be done in the liquid phase. Syngas , CO and H2, usually from steam reforming of natural gas, can also be the basis for vinyl chloride. This is a multistq) pathway through methanol or methyl acetate made from syngas reacting with syngas. 

The permeation, selectivity, and flux variation with methanol concentration has been explained using the solubiUty parameter approach Copolymers of acrylonitrile with methyl methacrylate and vinyl acetate showed good selectivity and moderate flux Membrane (I) gave high selectivity and acceptable flux... 

Coextrusion of L-lactide (a cyclic dimer lactone of lactic acid) with hydroxy-terminated poly(caprolactone) in the presence of stannous octoate gave a block copolymer.74 Block copolymers can also be used as compatibilizers for the homopolymers, in addition to having interesting properties in their own right.75 Copolymers of ethylene and vinyl acetate can be treated with methanol and a little sodium methoxide to remove some of the acetate groups from the copolymer.76 The by-product methyl acetate comes out the vent of the extruder. n-Butyl alcohol can be used in the same way.77 The product copolymer is useful as a gas barrier coating on films for packaging food. 

Carbonylation of methyl acetate, developed in particular by Hakoru This method is based on the use of synthesis gas to produce successively methanol, methyl acetate, and acetic anhydride jointly with ethyiidene diacetate, which then decomposes to vinyl acetate and acetic add, which is recycled to methyl acetate synthesis. The overall reaction is the following ... 

The same reaction was attempted in the presence of oxygen by Wang et al. The reaction is conducted at 350 °C with acetone/methanol/02/N2 feed rates of 1.5/1.5/5.0/15.0 mL/min over various metal oxide catalysts supported on fluoro tetrasilicic mica. Over the Ti02 catalyst, the main products are methyl vinyl ketone, methyl ethyl ketone, and methyl acetate. The yields are 9.8, 0.023, and 1.3 mol%, respectively, at an acetone conversion of 11.6 the selectivity to methyl ethyl ketone is 85 mol% based on acetone. 

Reductive cleavage of the /tara-methoxyphenyl (PMP-) group released the primary alcohol and the compound was converted into the corresponding methyl glycoside upon reaction with methanol in the presence of PhsP.HBr [65]. Subsequently, the primary alcohol was replaced by iodine to yield 68 to pave the way for the introduction of the exomethylene functionality required for the key Perrier s carbocy-clization reaction. Carbocycle 70 was obtained after exposure of 5-enopyranoside 69 to Hg(OCOCp3)2 in acetone/acetate buffer and the subsequent p-elimination. The synthesis of the C-ring of the alkaloid was completed by 1,4-reduction and formation of the vinyl triflate 71 with the Comins reagent. 

A simple synthesis of a glycoside of DL-daunosamine has been devised by Matsumoto and his co-workers. In this approach 1-chloro-l, 4-hexadiene-3-one (77, obtained from crotonyl chloride and vinyl chloride) was converted into 1,1-ethylenedioxy-4 -hexen-3-one (78). cw-Hydroxylation of 78 afforded threo-A o-lon (79). Oximation of 79 and reduction of the oxime gave a single stereoisomeric aminodiol (80) which, after treatment with methanolic hydrogen chloride, yielded methyl a-DL-daunosaminide (74, R = H, R = Me) in 84% yield. Makin and co-workers described two methods leading to both stereoisomeric 2-deoxy-DL-pentoses in the form of their diethyl acetals. In the first method, the readily available 1,l-diethoxy-3-penten-5-ol (81) was directly cri-hydroxylated furnish-... 

An azeotropic mixture of methyl acetate and methanol is a common coproduct from the manufacture of poly(vinyl alcohol) from poly(vinyl acetate) in the presence of methanol and sodium methoxide. The polymerization of vinyl acetate in this azeotropic solution, with the total removal of oxygen from the system, and using conventional free radical initiators is said to afford high-molecular weight poly(vinyl acetate) [106]. 

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