Atmospheric ozonolysis study of methyl acrylate and methyl 3-methyl acrylate

Detailed reaction mechanisms of methyl acrylate (MA) and methyl 3-methyl acrylate (M3MA) with ozone have been investigated using quantum chemistry calculations based on the CCSD(T)/6-31G(d)+CF//B3LYP/6-31+G(d,p) level of theory. Possible reaction channels and products have been presented and discussed. The temperature-dependent and pressure-independent overall and site-specific rate constants are calculated by employing multichannel RRKM theory. The obtained overall rate constants (in cm³ molecule^?1 s^?1) based on the CCSD(T)+CF energies can be described as: $ k_{{({\text{MA}} + {\text{O}}_{ 3} )}} = 3. 7 4 \times 10^{ - 1 3} { \exp }\,( - 3 7 4 6. 1 2/T) $ and $ k_{{({\text{M3MA}} + {\text{O}}_{ 3} )}} = 5. 1 2 \times 10^{ - 1 3} { \exp }( - 3 3 5 4. 8 7/T) $ at 200–400 K and 760 Torr. Under atmospheric conditions, the dominant products of ozonolysis of MA and M3MA are methyl glyoxylate and formaldehyde, methyl glyoxylate and acetaldehyde, respectively. The results of theoretical study are in good agreement with the available experimental measurements. Researches on branching ratios and atmospheric lifetimes also have been obtained as complement to the experimental results.     

In situ generation of nitroxide from alkoxyamines for controlled acrylate polymerization

A general strategy for the controlled nitroxide-mediated polymerization of acrylates from alkoxyamines without addition of excess free nitroxide is outlined. 2,2-Dimethyl-3-(1-phenylethoxy)-4-phenyl-3-azapentane ( 1 ), prepared in one pot by the addition of 1-phenylethyl radicals to 2-methyl-2-nitrosopropane, is heated prior to the addition of monomer to afford a mixture of alkoxyamine 1 , free nitroxide, and 2,3-diphenylbutane. With a 30 min preheating period at temperatures up to 125 °C, the kinetics of the subsequent polymerization of n-butyl acrylate at 125 °C appear largely unaffected, though the ultimate molecular weight of the polymers is dependent upon the preheating temperature. The poly(n-butyl acrylate) samples, that result from this process, have much narrower molecular weight distributions than those which result in the absence of the preheating process. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5128–5136, 2006     

Copolymerizations involving methyl methacrylate,methyl acrylate,stilbene and p.fluorostilbene

Homopolymerizations and copolymerizations of methyl methacrylate (MMA) and methyl acrylate (MA) have been performed in the presence of either stilbene or p.fluorostilbene, labelled with carbon-14. It has been shown that at 60°C the polyMA radical is much more reactive than the polyMMA radical towards stilbene, the velocity constants for the reactions differing by a factor of about 300; similar results are found for p.fluorostilbene. The differences between the reactivities of the radicals are associated with steric effects arising from the presence of a methyl group at the alpha position in MMA.     

Base-promoted reaction of methyl 4,6-O-benzylidene-3-deoxy-hexopyranosid-2-ulose and various arylamines

Reaction of methyl 4,6-O-benzylidene-3(2)-deoxy-hexopyranosid-2(3)-ulose (1) with various arylamines under Bargellini reaction conditions was investigated. A series of unique enaminoketones 3-12 was obtained unexpectedly under basic conditions in 52-72% yield.     

Radical polymerization and copolymerization of methyl α-(2-carbomethoxyethyl)acrylate,a dimer of methyl acrylate,as a polymerizable α-substituted acrylate

Polymerization and copolymerization of methyl α-(2-carbomethoxyethyl)acrylate (MMEA), which is known as a dimer of methyl acrylate, were studied in relation to steric hindrance-assisted polymerization. The propagating polymer radical from MMEA was detected as a five-line spectrum and quantified by ESR spectroscopy during the bulk polymerization at 40–80°C. The absolute rate constants of propagation and termination (κ_p and κ_t) for MMEA at 60°C (κ_p = 19 L/mol s and κ_t = 5.1 × 10⁵ L/mol s) were evaluated using the concentration of the propagating radical at the steady state. The balance of the propagation and termination rates allows polymer formation from MMEA. The polymerization rate of MMEA at 60°C was less than that of MMA by a factor of about 4 at a constant monomer concentration. Although no influence of ceiling temperature was observed at a temperature ranging from 40 to 70°C, addition-fragmentation in competition with propagation reduced the molecular weight of the polymer. The content of the unsaturated end group was estimated to be 0.1% at 60°C to the total amount of the monomer units consisting of the main chain. MMEA exhibited reactivities almost similar to those of MMA toward polymer radicals. It is concluded that MMEA is one of the polymerizable acrylates bearing a substituted alkyl group as an α-substituent. Characterization of poly(MMEA) was also carried out. © 1996 John Wiley & Sons, Inc.     

Synthesis of nitrogen-containing benzoannulated eight- and nine-membered heterocycles from methyl 4-amino-3-iodobenzoate

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Organotin polymers—II.Copolymerization parameters for tributyltin methacrylate with methyl acrylate,ethyl acrylate,butyl acrylate and acrylonitrile

Copolymerizations of tributyltin methacrylate (M₁) with methyl acrylate, ethyl acrylate, n-butyl acrylate and acrylonitrile were carried out in solution at 70° using azobisisobutyronitrile as initiator. Copolymer compositions were determined by tin analysis; monomer reactivity ratios were calculated by Fineman-Ross and Kelen-Tüdös methods. The reactivities of acrylic esters decrease as the alkyl group becomes bulkier. Azeotropic copolymers could be formed from tributyltin methacrylate with butyl acrylate and with acrylonitrile. The structures of M₁ and its azeotropic copolymers have been investigated by infrared spectroscopy.     

Iodine-mediated one-pot synthesis of C-3 acylated indolizines from pyridines,aryl methyl ketones and acrylate derivatives

An I₂/CuI-promoted multi-component reaction from pyridines, aryl methyl ketones and electron deficient acrylates has been accomplished in a “one-pot” manner, which provides a straightforward and efficient access to C-3 acylated indolizines. The key intermediate of N-ylides is hypothesized to be generated in situ from pyridines and (hetero)aryl methyl ketones in the presence of iodine. This method has been applied in the synthesis of two molecules with anticonvulsant and anti-inflammatory activities.     

Pulsed laser terpolymerization of styrene,methyl methacrylate and methyl acrylate

The propagation rate coefficient of the terpolymerization of styrene, methyl methacrylate and methyl acrylate in bulk was successfully determined at three different monomer compositions. The temperature was varied between 18 and 80°C. The resulting data at 50°C were not in agreement with predictions according to the terminal model with binary reactivity ratios that have been determined by fitting copolymer composition data with the terminal model. This indicates that here also the penultimate unit affects the kinetics.     

Synthesis of heterocycles from the methyl ester of dehydroacetic acid

Conclusions The corresponding pyranopyrazole and pyranoisoxazole were obtained by the reaction of the methyl ester of dehydroacetic acid with phenylhydrazine and with hydroxylamine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1098–1100, May, 1971.     

Reactions of 2-iminothiazolidine derivatives with acrylonitrile,methyl acrylate,and methyl iodide

In all cases the cyanoethylation, carbomethoxyethylation, and methylation of 2-amino(imino)thiazoli(di)ne derivatives that are substituted at the exocyclic nitrogen atom lead to the simultaneous formation of isomeric products with 2-iminothiazolidine and 2-amino-²-thiazoline structures.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 563–566, April, 1990.     

Surface grafting of polyethylene by mutual irradiation in methyl acrylate vapor. I. γ irradiation

Mutual irradiation of polyethylene (PE) in methyl acrylate vapor easily forms a poly(methyl acrylate) (PMA) homopolymer layer on the inner graft copolymer layer consisting of both PE and PMA components as a result of the rapidly increasing surface-graft composition. This growth process of surface grafting has been found to provide some specific kinetic features different from those in other surface-grafting systems. With formation of the surface homopolymer layer, low- and highdensity PE sheets give the same grafting rate, whereas both sheets give different rates in grafting stages or conditions in which the homopolymer layer is not formed. This result indicates that most monomers, penetrating across the surface, are entrapped or consumed in the surface homopolymer layer; accordingly the rate becomes independent of the type of PE sheets that have significantly different diffusion coefficients. The thickness of the inner graft copolymer layer, which is kept constant after homopolymer-layer formation, increases with decreasing dose rate and with increasing monomer vapor pressure and temperature. This behavior can be qualitatively explained according to an equation for the initial steady-state grafting depth.     

PdCl_2-catalyzed heterocyclotrimerization in MeOH/scCO_2:A versatile approach to dimethyl pyridine-3,5-dicarboxylate from methyl acrylate and urea

A novel and green method for the synthesis of dimethyl pyridine-3,5-dicarboxylate has been developed. It is PdCl2-catalyzed heterocyclotrimerization of methyl acrylate with urea in methanol/supercritical carbon dioxide. The target compound was obtained with a 75% isolated yield under the optimized con-ditions.     

PdCl2-catalyzed heterocyclotrimerization in MeOH/scCO2: A versatile approach to dimethyl pyridine-3,5-dicarboxylate from methyl acrylate and urea

A novel and green method for the synthesis of dimethyl pyridine-3,5-dicarboxylate has been developed. It is PdCl₂-catalyzed heterocyclotrimerization of methyl acrylate with urea in methanol/supercritical carbon dioxide. The target compound was obtained with a 75% isolated yield under the optimized conditions.     

Base-promoted regioselective synthesis of 1,2,3,4-terahydroquinolines and quinolines from N-boc-3-piperidone

An efficient synthesis of 1,2,3,4-tetrahydroquinolines with donor and acceptor group has been delineated by base mediated ring transformation of 6-aryl-4-substituted-2H-pyran-2-one-3-carbonitriles by N-boc-3-piperidone followed by consecutive deprotection of Boc group under acidic conditions. This reaction involves 2 new bond formations namely C4a-C5 and C8a-C8 in order to create the nucleus. Various donor and acceptor functional groups like aryl, heteroaryl, nitrile, methylsulfanyl and secondary amine were installed in 1,2,3,4-tetrahydroquinolines. We extended our approach to synthesize the fused 1,2,3,4-tetrahydroquinolines by using 2-oxobenzo[h]chromenes as precursor. Further, we synthesized fused and isolated quinolines through aromatization of 1,2,3,4-tetrahydroquinolines by DDQ in excellent yields. Single-crystal X-ray analysis of the Boc protected tetrahydroisoquinoline 6t showed the steric hindrance between N-Boc and aryl group.     

Initialisation in RAFT-mediated polymerisation of methyl acrylate

Inhibition in Reversible Addition-Fragmentation chain Transfer (RAFT)-mediated polymerisations is currently a controversial issue; here we provide evidence that the slow "propagation" of the initiating and leaving group radicals during the early part (the period of consumption of the initial RAFT agent) of methyl acrylate RAFT-mediated polymerisation has characteristics similar to inhibition.     

Radical terpolymerization of sulfur dioxide,hexene-1, and methyl acrylate or methyl methacrylate

The radical terpolymerization of sulfur dioxide, hexene-1, and methyl acrylate has been investigated, and from the dilution effects on composition of the terpolymer it would seem reasonable to rule out the possibility of the participation of the charge-transfer complex in the propagation process. We have also carried out terpolymerization of sulfur dioxide, hexene-1, and methyl methacrylate and obtained a terpolymer having the block nature.     

Copolymerization behavior of 2-vinylbenzofuran: Copolymers of ethyl acrylate,n-butyl acrylate,and methyl methacrylate

The reactivity of 2-vinylbenzofuran in copolymerization reactions with n-butyl acrylate, ethyl acrylate, and methyl methacrylate was investigated. The vinylbenzofuran was found to be a very reactive monomer with the growing chain preferring to react with this monomer no matter what its terminus. Reactivity ratios were calculated using a nonlinear least squares error-in-variables method, which gives more reliable values of r₁ and r₂.