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1.
The anionic polymerization of lactams at low temperatures is not governed by thermodynamic equilibrium between the cyclic monomer and the linear polymer. On the basis of our reaction mechanism we propose therefore a new criterion (in contrast to the thermodynamic one) for estimating the chemical polymerizability of lactam: kendo/klactam, where klactam is the rate constant of alkaline hydrolysis of the lactam and kendo that of the endocyclic imide bond in the corresponding N-acyl lactam. The value thus found for α-piperidone and giving the theoretical polymerizability of this lactam accounts, however, only partially for its low polymerizability. Finally, the behavior of α-piperidone derivatives in α-pyrrolidone polymerization, as well as that of α-pyrrolidone and α-piperidone in polymerization in the presence of inorganic salts such as LiCl and LiSCN, shows that the unusually low ability of this lactam to polymerize could be explained in terms of the hydrogen-bond-rich structure of the resulting polymer appearing at a lower stage of conversion than that of other lactams and which might encage the active site situated at the end of the growing chain and thus hinder the access of lactam anion.  相似文献   

2.
The reaction of 1-methyl-4-piperidone ( 1 ) with amyl nitrate in the potassium tert-butoxidetetrahydrofuran system gave dipotassium 5-methyl-2-oxo-1,3-piperidinedinitronate ( 4 ) in 78% yield. Similar treatment of 1-methyl-2-pyrrolidinone ( 2 ) afforded potassium 3-methyl-2-oxopyrrolidinenitronate ( 7 ) in 85% yield. In contrast, the nitration of 1,3-dimethyl-2-pyrrolidinone ( 3 ) led to opening of the lactam ring with the formation of amyl 2-aza-2-methyl-5-nitrohexanoate ( 10 ) in 40% yield. Acidification of disalt 4 did not cause ring opening but gave the dipolar ion of 1-methyl-3-nitro 4-hydroxy-5-aci-nitro-Δ3-tetrahydropyridinium (6).  相似文献   

3.
1-(3-Oxo-5-methyl-4-hexen-1-yl)-2,5-dimethyl-4-piperidone, 5-(3-oxo-5-methyl-4-hexen-1-yl)-2, 5-dimethyl-4-piperidone, and 5-(3-oxo-5-methyl-4-hexen-1-yl)-1,2,5-trimethyl-4-piperidone were synthesized. In the absence of a catalyst,-dimethyldivinyl ketone adds to 2,5-dimethyl-4-piperidone at the 1-position, while in the presence of alkali it adds at the 5-position.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 350–351, March, 1971.  相似文献   

4.
Xanthobilirubic acid, 5-[1,5-didehydro-3-ethyl-4-methyl-5-oxo-2H-pyrrol-2-ylidene)methyl]-2,4-dimethyl-1H-pyrrol-3-propanoic acid, its methyl ester, amide, N-methylamide and dimethylamide, and kryptopyrromethenone have been synthesized and characterized spectroscopically. In d6-DMSO solution all pyrromethenones were monomeric, with lactam and pyrrole N-Hs H-bonded to solvent. In deuteriochloroform, the pyrromethenones preferred a dimeric form, with intramolecular H-bonding between the lactam C = 0 of one unit and the lactam and pyrrole N-Hs of the second.  相似文献   

5.
T. Fujii  S. Yoshifuji 《Tetrahedron》1970,26(24):5953-5958
In order to explain the difficulty in hydrolysing the lactam linkage of 1-benzyl-2-oxo-5-ethyl-4-piperidineacetic acid (XIV) under acid conditions, several model compounds such as 1-benzyl-2-piperidone (X), 1-benzyl-5-ethyl-2-piperidone (XI), 1-benzyl-4-ethyl-2-piperidone (XII) and 1-benzyl-2-oxo-4-piperidineacetic add (XIII) were prepared and their hydrolysis in boiling 6N HCl was studied. For each of the lactams, the hydrolysis was found to proceed to an equilibrium as shown in Table 1. Substituents at the 4- and 5-positions of the piperidone ring seemed to favour the ring form in the equilibrium between piperidones (X-XIV) and ω-amino acid hydrochlorides (type XV).  相似文献   

6.
Low-temperature polymerization of α-pyrrolidone, α-piperidone, and ?-caprolactam was examined by using the salts derived from NaAlEt4 and monomer, sodium lactamates, or the salt derived from AlEt3 and monomer as catalyst and with N-acetyl lactams, ethyl acetate, or lactones as initiator. Sodium lactamate catalyst gave unsatisfactory results in the cases of ethyl acetate or lactones initiators, and gave the following order for the relative efficiency of initiators: N-acetyl lactam > ?-caprolactone ≥ ethyl acetate > β-propiolactone. The polymerization results obtained by the salt from NaAlEt4 catalyst–ethyl acetate initiator system were nearly the same as those with N-acetyl lactam. The increases in the degree of polymerization and in the yield of polymer were observed in case of the salt from NaAlEt4 catalyst-lactone initiator system, particularly in the cases of α-piperidone and ?-caprolactam. Also an incorporation of initiator into polymer chain was observed.  相似文献   

7.
Polymerization of five-, six-, and seven-membered lactams by metallic potassium or MAlEt4 (where M is Li, Na, or K) as a catalyst and N-acyl lactam or diphenylketene as an initiator was carried out at temperatures below 80°C. By using MAlEt4 instead of a metallic potassium catalyst in the polymerization of α-piperidone the propagation was continued until the reduced viscosity of polymer reached a value of 0.9. The polymer obtained has a film-forming ability. The experimental results obtained in the gasometry suggest that MAlEt4 reacts with lactam to form such a complex of the type (where M is Li, Na, or K and X is an ethyl or 2-oxo-alkylene-imine group). The resulting complexes are considered to increase the solubility of catalyst and also to protect the polymer endgroups from side reactions by stabilizing the alkali metal as the complex. In addition, the mode of action of diphenylketene as an initiator was revealed by the facts that the corresponding N-diphenylacetyl lactam was obtained from the reaction of diphenyl ketene with lactam and N-diphenylacetyl lactam itself was useful for the polymerization of α-piperidone.  相似文献   

8.
Poly[4-(4-nitrobenzyloxy)styrene] was synthesized with a high degree of etherification by the reaction of poly(4-hydroxystyrene) (PHST) with p-bromomethylnitrobenzene (p-BMNB) using 1,8-diazabicyclo-[5,4,0]-7-undecene (DBU) in hexamethylphosphoramide (HMPA). Poly[4-(3-nitrobenzyloxy)styrene] and poly[4-(2-nitrobenzyloxy)styrene] were also prepared with a high degree of etherification by the corresponding reaction with m- or o-BMNBs. However, the degrees of etherification of PHST with these BMNBs were relatively low when the reactions were carried out in other aprotic polar solvents such as DMF, DMSO, and N-methyl-2-pyrrolidone. On the other hand, poly(4-introbenzyl methacrylate) (PPNBMA), poly(3-nitrobenzyl methacrylate) (PMNBMA), and poly(2-nitrobenzyl methacrylate) (PONBMA) were synthesized with a high degree of esterification by the reaction of poly(methacrylic acid) with the corresponding BMNBs using DBU in DMSO at 30°C. The photochemical properties of the resulting poly(nitrobenzyl methacrylate)s were examined, and it was found that the rates of photodecomposition of PPNBMA and PMNBMA were promoted by the addition of tributylamine and trifluoromethanesulfonic acid, respectively. However, the rate of photodecomposition of PONBMA was not affected by addition of the base or the acid.  相似文献   

9.
Oxazolidone group-containing vinyl monomers, 4-(2-oxo-3-oxazolidinyl)methylstyrene (OS) and 4-[2-(2-oxo-3-oxazolidinyl)ethoxy]methylstyrene (OES), were synthesized and their polymerization and copolymerization behaviors with styrene (St), p-methoxystyrene (PMS), and m-hydroxystyrene (MHS) were investigated. OS was prepared in 70% yield by the reaction of 2-oxazolidone with p-chloromethylstyrene in the presence of sodium hydride. OES was obtained by the similar reaction of p-chloromethylstyrene with N-hydroxyethyl-2-oxazolidone which was prepared by the reaction of 2-oxazolidone with ethylenecarbonate. Homopolymerization of OS and OES afforded mainly gelled polymers, but also soluble polymers on high dilution. In the copolymerization with styrene derivatives, an alternating nature was suggested from the copolymerization parameters obtained by either the nonlinear least-squares analysis method or the Fineman–Ross method. The alternating copolymerizability decreased in the following order: MHS > PMS > St. Q?e values of OS and OES were calculated and demonstrated that OS and OES behaved as stronger electron-accepting monomers in the copolymerization with MHS than in those with St and PMS. The copolymerization behavior of OS (OES) with MHS was compared with those of 4-(2-oxo-1-pyrrolidinyl)methylstyrene (PS) and 4-[2-(2-oxo-1-pyrrolidinyl)ethoxy]methylstyrene (PES). From an IR study examining the shift of carbonyl absorption by addition of MHS, the interaction which contributed to the increase of the alternating copolymerizability in the copolymerization of OS (OES) with MHS was concluded to be based on hydrogen bonding. © 1993 John Wiley & Sons, Inc.  相似文献   

10.
Two new routes to polyamides were established, based on the polycondensation of two new typical active diesters: the active diester of N-hydroxy-5-norbornene-2,3-dicarboximide, such as N,N′-(terephthaloyldioxy)bis(5-norbornene-2,3-dicarboximide), and the active diester of 3-hydroxy-4-oxo-3,4-dihydro-1,2,3-benzotriazine, such as 3,3′-(isophthaloyldioxy)bis(4-oxo-3,4-dihydro-1,2,3-benzotriazine) with diamines. The polycondensation occurred at room temperature in solution without added catalyst. Dipolar aprotic solvents which included dimethyl sulfoxide and N-methyl-2-pyrrolidone were used as solvents for polymerization. Before polymer synthesis the aminolysis of two active monoesters was carried out as a model compound study.  相似文献   

11.
Irradiation of 3,5-diphenyl- or 3-(p-tolyl)-5-phenyl-2-isoxazoline ( 12 and 13 , respectively) in benzene with a high-pressure mercury lamp yields 4,5-diphenyl- or 4-(p-tolyl)-5-phenyl-3-oxazoline ( 17 and 19 , respectively) and the β-amino-chalcones 18 or 20 in addition to benzaldehyde, benzonitrile and p-tolunitrile, respectively (scheme 6 and ‘Anmerkg.’ p. 2600). The 3-oxazolines 17 and 19 are formed by route a (scheme 8) via 3-phenyl- or 3-(p-tolyl)-2H-azirine ( 23 , R = H and CH3, respectively) and their photochemically rearranged successors, the nitrile methylides 24 , as intermediates. The discovery of this reaction has served as a basis for the quickly developing photochemistry of 3-aryl-2H-azirines [2] [24]. Photolysis of the 2-isoxazoline 13 in methanol leads to the formation of a mixture of syn/anti-p-tolyl trans-styryl ketoximes (syn/anti, trans- 30 ) and anti, cis- 30 , 2-(p-tolyl)-quinoline ( 29 ), the 4-hydroxymethylated derivative 32 of the latter (in small amounts), besides the β-aminochalcone 20 , benzaldehyde, p-tolualdehyde and p-tolunitrile (scheme 9). It could be shown that the stereoisomeric ketoximes 30 are photochemically interconvertible (scheme 12) and that at least one mechanism of formation of 2-(p-tolyl)-quinoline ( 29 ) is the photo-induced cyclisation of p-tolyl-cis-styryl ketoximes (cis- 30 ) (scheme 13). A tentative mechanism for the formation of p-tolual-dehyde is given in scheme 10; the crucial step is the protonation of p-tolunitrile methylide ( 24 , R = CH3) by methanol at the nitrile carbon atom, after which hydrolysis yields the aldehyde.  相似文献   

12.
Three bifunctional N-phenylmaleimide derivatives, N-[4-(2-hydroxy-3-methacryloyloxy propyloxycarbonyl)phenyl]male-imide (GMAPMI, 1), N-(4-methacryloyloxyphenyl) maleimide (MAPMI, 2) and 4-(4-maleimidobenzoyloxy)styrene (MIBOSt, 3) having radically polymerizable maleimide and vinyl groups together have been synthesized and polymerized. Polymerizations of the bifunctional maleimide monomers were carried out using a radical initiator at 55°C and the results were compared with those obtained by self-polymerization in the absence of ini-tors. All of the polymers obtained were insoluble in organic solvents owing to cross-linking between different functional groups. The reactivity for homopolymerization of monomer 3 is higher than that of monomers 1 and 2 because the styryl moiety of monomer 3 has better electron-donor strength than the methacrylate moiety. Under the same conditions, GMAPMI was copolymerized with N-vinyl-2-pyrrolidone and styrene as an electron-donor to give higher conversions by electron-donor/acceptor polymerization in which the maleimide moiety of GMAPMI mainly involved as an electron acceptor.  相似文献   

13.
Cyclization reactions with 2-(β-styryl)benzylamines 5-Phenyl-1H-2-benzazepines Cyclization of the urea derivative 3 with POCl3 to give 2-(4-methyl-1-piperazinyl)-4-phenylquinoline ( 4 ) was carried out in analogy to the quinoline synthesis of Foulds & Robinson. This reaction was used for the preparation of 2-benzazepines. The trisubstituted ureas 6 and 8 , derived from the 2-(β-styryl)-benzylamines 5 , were cyclized with POCl3 to yield the 3-amino-5-phenyl-1H-2-benzazepines 7 and 9 , respectively. Similarly, cyclization of the corresponding acetyl-derivatives 10 gave the 3-methyl-5-phenyl-1H-2-benzazepines 12 . On the other hand, the disubstituted urea 15 , cyclized under the same conditions to the 1-methyl-1-phenylisoindoline derivative 16 , and 2-(β-styryl)benzylamine ( 5a ) on treatment with phosgene gave the isoindoline 17 in an analogous manner.  相似文献   

14.
According to the AM1, PM3, HF/6-31G(d,p), and MP2/6-31G(d,p)//HF/6-31G(d,p) calculations, it is the lactam tautomer of 2-pyrrolidone that is thermodynamically most stable in both the gas phase and an aqueous solution. Analysis of the PM3 data with consideration of the medium showed that the tautomeric equilibrium of 2-pyrrolidone (pyrroline-2-ol) in aqueous solution is shifted to the lactim form, which thus can be involved in complexation with palladium(II). 2-Pyrrolidone was found to be protonated at the O atom in both the gas phase and aqueous solution, in agreement with the concept of the mesomeric displacement of the electron density in the amide fragment. The aqueous medium stabilizes the lactim tautomer of 2-pyrrolidone more strongly than the lactam tautomer and the O-protonated cyclic amide than the N-protonated one. The stereoselectivity of complexation between palladium(II), chloride ion, and pyrroline-2-ol was explained. The initially formed tetragonal-pyramidal adduct with an axial organic ligand undergoes rearrangement into an intermediate with an extra axial Cl atom, which is a precursor of the cis-product. The thermodynamically less stable cis-isomer of the complex [PdCl2(pyrrolin-2-ol)2] is formed from the thermodynamically most favorable intermediate in associative nucleophilic substitution. At the supramolecular level, the cis-product can be stabilized by intermolecular dipole-dipole association in the crystal.__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 7, 2005, pp. 523–529.Original Russian Text Copyright © 2005 by Pankratov, Borodulin, Chaplygina.  相似文献   

15.
p-Vinylphenylsulfonylnitromethane ( 3 ) was synthesized by the reaction of sodium p-styrenesulfinate with nitromethane. Free radical copolymerizations of 3 with styrene and N-vinyl-2-pyrrolidone provided soluble copolymers. Conversions of RCH2X (X = Br, OAc) with the copolymers as reagents proceeded in a different manner from the corresponding lowmolecular-weight compound, phenylsulfonylnitromethane, to afford RCOOH in addition to the expected RCH2CH2NO2 and RCH2COOH; no nitriles were formed.  相似文献   

16.
Syntheses and reactions of 4-carboxy-2-pyrrolidone, 6,6-dimethyl-4-carboxy-2-piperidone, and 5,5-dimethyl-4-carboxy-2-pyrrolidone are described. Whereas 4-carboxy-2-pyrrolidone polymerizes upon heating to form a polyimide, the two lactams containing geminal dimethyl groups undergo isomerization. The 6,6-dimethyl-4-carboxy-2-piperidone isomerizes to 5,5-dimethyl-3-carboxymethyl-2-pyrrolidone, and 5,5-dimethyl-4-carboxy-2-pyrrolidone affords isopropylidene succinimide. Possible mechanisms for these reactions are discussed.  相似文献   

17.
Preparation of Styryl and Stilbenyl Derivatives of Pyrimidines 2- and 4-(p-Tolyl)-substituted pyrimidines react with anils of hetero-aromatic aldehydes in the presence of dimethylformamide and potassium hydroxide or potassium t-butoxide to yield the corresponding 2- and 4-[4″-(heteroaryl)stilben-4′-yl]pyrimidines or the 2- and 4-[a-(heteroaryl)-4′-styryl]pyrimidines respectively (‘Anil synthesis’). Furthermore, the Schiff′s bases derived from p-chloroaniline and 4-(pyrimidine-2-yl and 4-yl)benzaldehydes give, with methyl- and with p-tolyl-substituted heterocycles, the corresponding heterocyclic substituted styryl and stilbenyl derivatives. Alkyl-, alkoxy- or phenyl-substituted pyrimidines undergo also the ‘Anil synthesis’.  相似文献   

18.
The densities of the ternary-pseudobinary mixtures [(styrene + ethyl acetate or benzene) + (N-methyl-2-pyrrolidone + ethyl acetate or benzene)], formed by adding the third component (ethyl acetate or benzene) to the binary system (styrene + ethyl acetate), have been measured as a function of composition by means of a vibrating-tube densimeter at atmospheric pressure at 298.15 K. The excess molar volumes V m E were calculated from the densities and correlated using the Redlich–Kister equation to estimate the coefficients and standard errors. The experimental and calculated quantities are used to discuss the mixing behavior of the components. The results show that the third component, ethyl acetate or benzene, have quite different influences on the interaction between styrene and N-methyl-2-pyrrolidone.  相似文献   

19.
Thermal decarboxylation of 3-p-toluoyl-1,2-dihydro-4H-pyrrolo[5,1-c][1,4]benzoxazine-1, 2,4-trione resulted in 2-oxo-2H-1,4-benzoxazin-3-yl(p-toluoyl)ketene; the latter under-goes [4+2]-cycloaddition withp-bromobenzaldehyde to form 1-p-bromophenyl-4-p-toluoyl-1, 3-dihydro-5H-[1,3]oxazino[4,3-c][1,4] benzoxazine-3,5-dione. The crystal and molecular structure of the latter has been studied by X-ray analysis.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1633–1636, September, 1993.  相似文献   

20.
Rearrangements of 3-aza-A-homo-4α-androsten-4, 17-dione oxime produced a mixture of the normal lactam product and the product of a “second order” cleavage, an unsaturated nitrile. The lactam 3, 17α-di-aza-A, D-bishomoandrost-4α-ene-4, 17-dione was also obtained from the rearrangement of the syn-3-oxo-13α-amino-13, 17-seco-4-androsten-17-oic-13, 17-lactam oxime. The resolution of syn- and anti-isomers of VIII was effected by column chromatography and their structure was determined by spectral data.  相似文献   

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