9003-09-2

Usage

Definition

ChEBI: A macromolecule composed of repeating methoxyethyl groups.

Preparation

Vinyl ethers are prepared by reaction of acetylene and alcohols in the presence of the potassium alkoxide as catalyst:For the production of polymers, methyl, ethyl and isobutyl vinyl ethers are the most common monomers. Vinyl ethers are susceptible only to cationic polymerization. In a typical process, methyl vinyl ether is agitated with boron trifluoride (BF 3. 2H20). The temperature is kept at about l0℃ by cooling for 3-4 hours; the reactor is then sealed and the temperature allowed to rise to 100°C. Reaction is complete in about 10 hours and the polymer is obtained as a viscous mass. It is interesting to note that poly(vinyl isobuty ether) may be obtained in crystalline form by conducting polymerization at - 80° to -60°C in liquid propane using boron trifluoride etherate as initiator. This was the first stereoregular polymerization to be achieved. Incidentally, isotactic polymer has also been prepared by the use of Ziegler-Natta type catalysts and this was the first indication that these catalysts could polymerize a suitable monomer by a cationic mechanism.Poly(vinyl methyl ether) is water-soluble and is used in adhesive and textile sizes. The ethyl and isobutyl polymers find use in pressure-sensitive adhesives.

InChI:InChI=1/C3H6O/c1-3-4-2/h3H,1H2,2H3

Upstream product

• 67-56-1 methanol 
• 75-01-4 chloroethylene 
• 534-15-6 1,1-dimethoxyethane 
• 74-86-2 acetylene 
• 503-30-0 trimethylene oxide 
• 14604-48-9 vinyl cation 
• 110-49-6 2-methoxyethyl acetate 
• 108-20-3 di-isopropyl ether 
• 20615-69-4 O-methylated acetaldehyde 
• 98577-44-7 1,1-bis(chloromethyl)-2,2-dibromocyclopropane 
• 84050-93-1 N₁,N₃-(2-methoxyethyl)-N₁-nitrosothiourea 
• 84369-94-8 1-methoxy-1-<(1-methylethenyl)oxy>-ethane 
• 75-07-0 acetaldehyde 
• 77-78-1 dimethyl sulfate 

Downstream Products

• 342605-28-1 5-methoxy-2-phenylethynyl-3-(toluene-4-sulfonyl)-oxazolidine 
• 63591-58-2 5-methoxy-2-propenyl-3-(toluene-4-sulfonyl)-oxazolidine 
• 342409-07-8 2-isopropenyl-5-methoxy-3-(toluene-4-sulfonyl)-oxazolidine 
• 343611-52-9 5-methoxy-2-methyl-2-(2-methyl-propenyl)-3-(toluene-4-sulfonyl)-oxazolidine 
• 62472-51-9 2,2-diisobutyl-5-methoxy-3-(toluene-4-sulfonyl)-oxazolidine 
• 63777-03-7 6-methoxy-4,4-dimethyl-1,3-diphenyl-1,4,5,6-tetrahydro-pyrano[2,3-c]pyrazole 
• 63777-02-6 6-methoxy-4,4-dimethyl-1-phenyl-1,4,5,6-tetrahydro-pyrano[2,3-c]pyrazole 
• 62642-54-0 2r-benzyl-5t-methoxy-3-(toluene-4-sulfonyl)-oxazolidine 
• 62642-56-2 2r-(4-fluoro-phenyl)-5t-methoxy-3-(toluene-4-sulfonyl)-oxazolidine 
• 62642-58-4 5t-methoxy-2r-(4-nitro-phenyl)-3-(toluene-4-sulfonyl)-oxazolidine 
• 54123-71-6 1-phenyl-2-methoxy-2-propen-1-one 
• 62472-50-8 5-methoxy-2,2-dimethyl-3-(4-nitro-benzenesulfonyl)-oxazolidine 
• 62472-54-2 2r-benzyl-5t-methoxy-2-methyl-3-(toluene-4-sulfonyl)-oxazolidine 
• 67038-71-5 (2-Iodo-2-methoxy-ethoxymethyl)-benzene 

Relevant academic research and scientific papers

Phosphine-Catalyzed Vinylation at Low Acetylene Pressure

The vinylation of various nucleophiles with acetylene at a maximum pressure of 1.5 bar is achieved by organocatalysis with easily accessible phosphines like tri-n-butylphosphine. A detailed mechanistic investigation by quantum-chemical and experimental methods supports a nucleophilic activation of acetylene by the phosphine catalyst. At 140 °C and typically 5 mol % catalyst loading, cyclic amides, oxazolidinones, ureas, unsaturated cyclic amines, and alcohols were successfully vinylated. Furthermore, the in situ generation of a vinyl phosphonium species can also be utilized in Wittig-type functionalization of aldehydes.

Method for synthesizing vinyl methyl ether by using ethylene glycol dimethyl ether

The invention discloses a method for synthesizing vinyl methyl ether by using ethylene glycol dimethyl ether. The synthesis method comprises the step of carrying out elimination reaction on ethylene glycol dimethyl ether under the catalytic action of solid alkali to obtain vinyl methyl ether and methanol, wherein the solid alkali is magnesium oxide, cerium dioxide, calcium oxide or calcium-magnesium mixed oxide, and in the calcium-magnesium mixed oxide, the molar ratio of calcium to magnesium is 0.1-4. According to the method for preparing the vinyl methyl ether by catalyzing the ethylene glycol dimethyl ether with the solid alkali, provided by the invention, the raw materials are wide in source and green; the catalyst is efficient, cheap and good in stability; the yield of the target product can reach 80%; the byproduct methanol can be recycled to prepare reaction raw materials; and the method is low in equipment requirement and small in investment, and has very important practical application value.

Thermally Stable Half-Sandwich Benzhydryl Ln(II) (Ln = Sm, Yb) Complexes Supported by Sterically Demanding Carbazolyl and Fluorenyl Ligands

A series of new isolable and thermally stable half-sandwich Ln(II) benzhydryl complexes coordinated by the sterically demanding ligands tert-butylcarbazol-9-yl [tBu4Carb]Ln[(p-tBu-C6H4)2CH](L) (Ln = Sm, L = DME (4); Ln = Yb, L = DME (5); Ln = Yb, L = TMEDA (6)) and 2,7-di-tert-butyl-fluoren-9-trimethylsilylyl [2,7-tBu2-9-Me3Si-C13H6]Yb[(p-tBu-C6H4)2CH](DME) (7) were synthesized by the alkane elimination reaction of [(p-tBu-C6H4)2CH]2Ln(Ln) (Ln = Sm, Yb) with tBu4CarbH and 2,7-tBu2-9-Me3Si-C13H7. X-ray analysis revealed that in 4, 5, and 7 the benzhydryl ligand is coordinated to the metal ion in an ν3 coordination mode, while in 6 it is ν1-bound. The type of coordination of the benzhydryl ligands in diamagnetic 5-7 is retained in their C6D6 solutions. Complexes 4-7 demonstrated unprecedented thermal stability and do not undergo decomposition after heating their solutions in C6D6 or toluene at 100 °C for 72 h. The reactions of [tBu4Carb]Ln[(p-tBu-C6H4)2CH](DME) (Ln = Sm (4), Ln = Yb (5)) with an excess of DME led to the formation of the symmetrical bis(carbazolyl) complex products [tBu4Carb]2Ln(DME)4 (Ln = Sm (8), Yb (9)) isolated in the form of separated ion pairs.

Influence of Boiling on the Radiolysis of Diglyme

The radiolysis of diethylene glycol dimethyl ether (diglyme) in a boiling state has been studied for the first time. Boiling facilitates the cleavage of internal C–O bonds, weakens the cage effect and diglyme regeneration processes, and facilitates the exchange and dimerization reactions of radicals. As compared with radiolysis at room temperature, the amount of unsaturated products of diglyme fragmentation formed during irradiation in the boiling state is smaller by a factor of 4, and the disproportionation products of heavy radicals are found in negligible amounts, if any. The yield of radiolytic decomposition of diglyme under boiling conditions is ～15 molecule/100 eV, which is higher than that at room temperature by a factor of almost 1.5.

Chloro and alkyl rare-earth complexes supported by ansa-Bis(amidinate) ligands with a rigid o-phenylene linker. Ligand steric bulk: A means of stabilization or destabilization?

ansa-Bis(amidinate) ligands with a rigid o-phenylene linker, C 6H4-1,2-{NC(tBu)N(2,6-R2C6H 3)H}2 (R = Me (1), iPr (2)), were successfully employed for the synthesis of rare-earth chloro and alkyl species. The reaction of dilithium derivatives of 1 and 2 with LnCl3 (Ln = Y, Lu) afforded the monomeric bis(amidinate) chloro lanthanide complexes [C6H 4-1,2-{NC(tBu)N(2,6-R2C6H3)} 2]Y(THF)(μ-Cl)2Li(THF)2 (R = Me (3), iPr (5)) and [C6H4-1,2-{NC(tBu)N(2,6-Me2C 6H3)}2]LuCl(THF)2 (4). Bis(amidinate) ligands in complexes 3 and 4 are coordinated to the metal atoms in a tetradentate fashion, while the bulkier ligand in 5 is tridentate. The alkane elimination reactions of 1 and 2 with equimolar amounts of (Me 3SiCH2)3Ln(THF)2 (Ln = Y, Lu) allowed us to obtain the monoalkyl complexes [C6H4-1,2- {NC(tBu)N(2,6-R2C6H3)}2]Ln(CH 2SiMe3)(THF)n (Ln = Y, R = Me, n = 1 (6); Ln = Lu, R = Me, n = 1 (7); Ln = Y, R = iPr, n = 2 (8)). The kinetics of thermal decomposition of complexes 6-8 were measured, and for 6 the activation energy was obtained from the temperature dependence of the rate constants (E a = 67.0 ± 1.3 kJ/mol). Complexes 6 and 7 turned out to be inert toward H2 and PhSiH3. Surprisingly, complex 8 was inert toward H2 and PhSiH3 but rapidly cleaved C-O bonds of DME. The reaction resulted in the formation of the methoxy complex {[C 6H4-1,2-{NC(tBu)N(2,6-iPr2C6H 3)}2]Y(μ2-OMe)]}2(μ 2-DME) (9) and methyl vinyl ether.

Competition between reaction and intramolecular energy redistribution in solution: Observation and nature of nonstatistical dynamics in the ozonolysis of vinyl ethers

Experimental product ratios in ozonolyses of alkyl vinyl ethers in solution do not fit with expectations based on statistical rate theories. The selectivity among cleavage pathways increases with the size of the alkyl group but to an extent that is far less than RRKM theory would predict. Trajectory studies account for the observed selectivities and support a mechanism involving a competition between cleavage of the primary ozonide and intramolecular vibrational energy redistribution. A statistical model is presented that assumes that RRKM theory holds for a molecular subset of the primary ozonides, allowing the rates of energy loss from the ozonides to be estimated from the observed product ratios.

Pyrolysis of α- and β-heteroatoms substituted ethyl phenyl sulfoxides

A study on the mechanism of the thermal decomposition of α- and β-heteroatoms substituted ethyl phenyl sulfoxides was carried out using 1-chloroethyl phenyl sulfoxide (1); two diastereomeric 1-acetoxyethyl (substituted phenyl) sulfoxides (2a) and (2b); and 2-chloroethyl phenyl, 2-bromoethyl phenyl, and 2-methoxyethyl phenyl sulfoxides (3, 4, 5). The rate of pyrolysis of 1 was 4.8 times faster at 160°C than that of ethyl phenyl sulfoxide used as a reference, while those of 2a and 2b were 107 and 155 times faster, respectively. The results indicate that the lone pair of electrons on the α-heteroatoms has a larger rate acceleration effect than the electronegativity of them. The substituent effects of the phenyl group of 2a and 2b gave positive Hammett ρ-values (ρa= 0.76 and ρb= 0.80 vs. σ). Activation parameters for 2a and 2b are as follows: 2a, ΔH?= 112 kJmol-1, ΔS?= -20 JK-1mol-1; 2b, ΔH?= 107 kJmol-1, ΔS?= -29 JK-1mol-1. Large deuterium kinetic isotope effects for 1-acetoxyethyl-2,2,2-d3 phenyl sulfoxides (2ad and 2bd) were observed (kH/kD= 3.5 ～ 4.1). These results suggest that the pyrolysis of -heteroatom substituted ethyl phenyl sulfoxides proceeds via a five-membered transition state deviated to E1-like in character. On the other hand, from the results of kinetics for the pyrolysis of 3, 4, and 5, no effect by the β-halogen atoms or some deceleration effect by the β-methoxy group was observed. Thus the reaction seems to proceed via an E1-like mechanism. Copyright Taylor & Francis Group.

CONTINUOUS METHOD FOR PRODUCING METHYL VINYL ETHER

The invention relates to a method for continuously producing methyl vinyl ether by reacting methanol with ethyne in the liquid phase in the presence of a basic alkali metal compound or alkaline earth metal compound at a temperature ranging from 40 to 300 °C and under a pressure ranging from 0.1 to 5 MPa abs. According to the invention, the reaction is carried out in the absence of a continuous gas phase and with a methyl vinyl ether concentration in the entire liquid phase of = 30 % by weight.

Mechanism and structure-reactivity correlation in the homogeneous, unimolecular elimination kinetics of 2-substituted ethyl methylcarbonates in the gas phase

The gas-phase elimination kinetics of 2-substituted ethyl methylcarbonates were determined in a static reaction system over the temperature range of 323-435 °C and pressure range 28.5-242 Torr. The reactions are homogeneous, unimolecular and follow a first-order rate law. The kinetic and thermodynamic parameters are reported. The 2-substituents of the ethyl methylcarbonate (CH3OCOOCH2CH2Z, Z = substituent) give an approximate linear correlation when using the Taft-Topsom method, log(k z/kH)= -(0.57 ± 0.19)σα + (1.34 ± 0.49)σR (r = 0.9256; SD = 0.16) at 400 °C. This result implies the elimination process to be sensitive to steric factors, while the electronic effect is unimportant. However, the resonance factor has the greatest influence for a favorable abstraction of the β-hydrogen of the C3- H bond by the oxygen carbonyl. Because ρα is significant, a good correlation of the alkyl substituents of carbonates with Hancock's steric parameters was obtained: log(kR/kH versus Esc for CH 3OCOOCH2CH2R at 400°C, R = alkyl, δ= -0.17 (r=0.9993, SD = 0.01). An approximate straight line was obtained on plotting these data with the reported Hancock's correlation of 2-alkyl ethylacetates. This result leads to evidence for the β-hydrogen abstraction by the oxygen carbonyl and not by the alkoxy oxygen at the opposite side of the carbonate. The carbonate decompostion is best described in terms of a concerted six-membered cyclic transition state type of mechanism. Copyright

Trends in alkyl substituent effects on nucleophilic reactions of carbonyl compounds: Gas phase reactions between ammonia and R1R2COCH3+ oxonium ions

The reactivity of carbonyl substituted methyl oxonium ions (R1R2COCH3-) towards ammonia has been investigated using an FT-ICR mass spectrometer and ab initio calculations. The monosubstituted ions (R1=H: R2 = H, CH3, C2H5 and i-C3H7) show different reaction patterns with variable degree of: (1) nucleophilic substitution, (2) addition elimination and (3) proton transfer, when reacted with ammonia. In all cases addition-elimination dominates over nucleophilic substitution, and the observed reactions are slow. The trends in reactivity are consistent with the alkyl group's electronic properties, as expressed by a single parameter linear or slightly non-linear model.