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1.
An economical one-pot synthesis of (-)-dimethyl 2,3-O-benzylidene-L-tartrate [(4R, 5S)-4,5-bis(methoxycarbonyl)-2-phenyl-1,3-dioxolane] and its enantiomer from the corresponding tartaric acids is reported in 83-91% yield. The desired benzylidene tartrate is obtained by reaction of tartaric acid and benzaldehyde (1.5 equiv) in the presence of p-toluenesulfonic acid in methanol followed by the addition of 3 equiv of trimethyl orthoformate, which reacts with the water generated in the reaction. 相似文献
2.
Liwei Cao Charles U. Pittman 《Journal of polymer science. Part A, Polymer chemistry》1999,37(15):2823-2840
Carbon black-supported sulfuric acid or BF3·Et2O-initiated polymerizations of 2-methylene-4,4,5,5-tetramethyl-1,3-dioxolane (1), 2-methylene-4-phenyl-1,3-dioxolane (2), and 2-methylene-4-isopropyl-5,5-dimethyl-1,3-dioxane (3) were performed. 1,2-Vinyl addition homopolymers of 1–3 were produced using carbon black-supported H2SO4 initiation at temperatures from 0°C to 60°C whereas both ring-opened and 1,2-vinyl structural units were present in the polymers using BF3·Et2O as an initiator. Cationic polymerizations of 2-methylene-1,3-dithiolane (4) and copolymerization of 4 with 2-methylene-4-(t-butyl)-1,3-dioxolane (5) were initiated with either carbon black-sulfuric acid or BF3·Et2O. Insoluble 1,2-vinyl addition homopolymers of 4 were obtained upon initiation with the supported acid or BF3·Et2O. A soluble copolymer of 2-methylene-1,3-dithiolane (4) and 4-(t-butyl)-2-methylene-1,3-dioxolane (5) was obtained upon BF3·Et2O initiation. This copolymer is composed of three structural units: a ring-opened dithioester unit, a 1,2-vinyl-polymerized 1,3-dithiolane unit, and a 1,2-vinyl polymerized 4-(t-butyl)-1,3-dioxolane unit. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2823–2840, 1999 相似文献
3.
Oxidation of 1,3-thiazolidines 3 gave a mixture of cis- and trans-sulfoxides 4 and 5 , major and minor, respectively. In the presence of an acid catalyst both the cis and trans sulfoxides underwent ring expansion reaction to produce dihydro-1,4-thiazines 2 in good yields. Under neutral conditions (100°/DMF) the cis-sulfoxides afforded a sigmatropic rearrangement with the 2-methylene group to generate probable sulfenic acids 6 followed by dehydration to 2, while the trans isomer rearranged more slowly involving the 2-methyl group to form isomeric dihydrothiazines 18 possibly via sulfenic acids 7. Structures and isomerization of the cis- and trans-sulfoxides are also discussed. 相似文献
4.
Stannic tetrachloride was an efficient Lewis acid catalyst for the aza-acetalization of aromatic aldehydes with o-arylaminomethyl phenols, and a series of novel aryl substituted 3,4-dihydro-2H-1,3-benzoxazines were prepared in good yields under mild conditions. SnCl4 was a more efficient catalyst for the reaction than p-toluenesulfonic acid, sulfuric acid, and aluminium chloride. 相似文献
5.
The reactions of 1,1-diphenylethene, 1,1-bis(4-chlorophenyl)ethene, 1,1-bis(4-methylphenyl)ethene, and 1,1-bis(4-methoxyphenyl)ethene with 3,5-diacetyl-2,6-heptanedione in the presence of manganese(III) acetate in acetic acid at 80° yielded 4,6-diacetyl-8,8-diaryl-1,3-dimethyl-2,9-dioxabicyclo[4.3.0]non-3-enes (41-48%), 5-acetyl-2,2-diaryl-6-methyl-2,3-dihydrobenzo[b]furans (20–21%), 3-acetyl-5,5-diaryl-2-methyl-4,5-dihydrofurans (5–10%), and benzophenones (3–7%). Similarly, the reactions of 1,1-diarylethenes with dimethyl 2,4-diacetyl-1,5-pentanedioate or diethyl 2,4-diacetyl-1,5-pentanedioate gave the corresponding 4,6-bis(alkoxycarbonyl)-8,8-diaryl-1,3-dimethyl-2,9-dioxabicyclo[4.3.0]non-3-enes in moderate yields. 相似文献
6.
Tomihiro Nishiyama Yoshiaki Iwasaki Fukiko Yamada 《Journal of heterocyclic chemistry》1983,20(2):479-481
Five 6-phenyl-5,6,7,8-tetrahydro-4H-1,3,6-dioxazocines were synthesized by the reaction of the corresponding N,N-bis(2-hydroxypropyl)- and N,N-bis(2-hydroxyethyl)chloroanilines with paraformaldehyde in the presence of p-toluenesulfonic acid. 相似文献
7.
I. B. Dzvinchuk 《Chemistry of Heterocyclic Compounds》2009,45(1):85-92
Three-component cyclocondensation involving p-(dimethylamino)benzaldehyde, 2-phenacylazahetero-cycle, and a 1,3-[N,C]-nucleophile
(3,5-dimethoxyaniline, 6-amino-1,3-dimethylpyrimidine-2,4-dione, 1-amino-3-methyl-5-phenylpyrazole) in boiling acetic acid
is accompanied by aromatization of the initially formed annelated 4-(p-dimethylaminophenyl)-3-hetaryl-2-phenyl-1,4-dihydropyridines, the direction of which, with splitting off the dimethylaminophenyl
substituent or its retention, is determined by the basicity of the hetaryl residue and the structure of the second ring, constructed
on the binucleophile. A possible reaction mechanism is discussed.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 101-109, January, 2009. 相似文献
8.
Mixtures of cis and trans 1,3-oxazolidin-4-ones were obtained by cyclodehydration, in the presence of p-toluenesulfonic acid or boron trifluoride etherate, of lactamide and N-methyl-lactamide with aromatic and aliphatic aldehydes. The products were separated by column (silica) chromatography and their configurations were determined. 相似文献
9.
R. Radovanovi-Kiprijanova D. Fle 《Journal of polymer science. Part A, Polymer chemistry》1975,13(5):1141-1146
The monomers trans-(R)(–)-5-phenyl-1,3-hexadiene (I) and trans-(R)(–)-6-phenyl-1,3-heptadiene (II) were prepared by dehydration of (R)(–)-3-acetoxy-5-phenyl-1-hexene and (R)(–)-3-acetoxy-6-phenyl-1-heptene, respectively. Monomers I and II were polymerized in heptane with three catalyst systems: γ-TiCl3–Al(i-Bu)3, VCl3–Alet3, and nBuLi. Polymers of identical structures were obtained with all three catalysts; according to infrared and NMR spectra, only the 1,4 structure was present. Acetone-insoluble fractions of poly-I and poly-II have higher optical rotations than the corresponding monomers ([M]D of poly-I, -46.45°, of monomer I, -28.6°: [M]D of poly-II, -46.8°, of monomer II, -32.55°). There is no difference in the rotation of poly-I and poly-II. 相似文献
10.
Robert Y. Ning Pradeep B. Madan Leo H. Sternbach 《Journal of heterocyclic chemistry》1974,11(2):107-111
Methods for the synthesis of the biologically active 7-acetyl-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one ( 6 ) are described. This includes two new methods for the preparation of 5-acetyl-2-aminobenzophenone ( 4 ). The crucial steps in these syntheses involve, respectively, the oxidation of an ethyl group to an acetyl group with permanganate or ceric ions ( 2 → 3; 5 → 6 ), the selective reaction of methyl lithium with the cyano group of 7-cyano-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one ( 8 ) and the efficient condensation of benzyl cyanide with the ethylene ketal of p-nitroacetophenone to form the anthranil 11 . 相似文献
11.
Successful dihydridocarbonyltris(triphenylphosphine)ruthenium (Ru-complex) catalyzed polymerization of 4-acetylstilbene with 1,3-divinyltetramethyldisiloxane to yield poly(3,3,5,5-tetramethyl-4-oxa-3,5-disila-1,7-heptanylene-alt-4-acetyl-3,5-stilbenylene) is reported. Polymerization results from Ru-complex catalyzed activation of aromatic C-H bonds which are ortho to the acetyl for selective anti-Markovnikov addition across the terminal C-C double bonds of 1,3-divinyltetramethyldisiloxane. The internal C-C double bond of 4-acetylstilbene does not react. 相似文献
12.
Yoichi Hiraguri Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》1989,27(13):4403-4411
2-Methyl-2-phenyl-4-methylene-1,3-dioxolane ( IIa ), 2-ethyl-2-phenyl-4-methylene-1,3-dioxolane ( IIb ), 2-phenyl-2-(n-propyl)-4-methylene-1,3-dioxolane ( IIc ), 2-phenyl-2-(i-propyl)-4-methylene-1,3-dioxolane ( IId ), 2-(n-heptyl)-2-phenyl-4-methylene-1,3-dioxolane ( IIe ), 2-methyl-2-(2-naphthyl)-4-methylene-1,3-dioxolane ( IIf ), and 2,2-diphenyl-4-methylene-1,3-dioxolane ( IIg ) were prepared and polymerized in the presence of a radical initiator. IIa–IIf were found to undergo vinyl polymerization with ring-opening reaction accompanying the elimination of ketone groups in bulk. IIg was found to undergo the quantitative ring-opening reaction accompanying the elimination of benzophenone in solution to obtain polyketone without any side reaction. 相似文献
13.
Kuklin V. N. Mikhailov L. E. Mironova G. A. Ivin B. A. 《Russian Journal of General Chemistry》2009,79(10):2212-2219
Reactions of 2-aryl-4-chloro-6H-1,3-thiazin-6-ones with sodium sulfide in aqueous alcohol at 18–20°C led to the formation of a readily separable mixture
of 2-aryl-4-sulfanyl-6H-1,3-thiazin-6-one sodium salts (yield >70%) and bis(2-aryl-6-oxo-6H-1,3-thiazin-4-yl) sulfides (<10%). The latter can also be obtained in more than 50% yield by treatment of 2-aryl-4-sulfanyl-6H-1,3-thiazin-6-one sodium salts with 2-aryl-4-chloro-6H-1,3-thiazin-6-ones. Methylation of 2-aryl-4-sulfanyl-6H-1,3-thiazin-6-ones afforded the corresponding methylsulfanyl derivatives (yield >90%) regardless of the alkylating agent,
solvent, temperature, reactant concentration, and their ratio. 2-Aryl-4-sulfanyl-6H-1,3-thiazin-6-ones in the crystalline state and in solutions in polar and nonpolar protic and aprotic solvents exist preferentially
as 4-sulfanyl-6-oxo tautomers, and they undergo almost complete ionization in neutral aqueous, alcoholic, and aqueous-alcoholic
media (pK
a = 4.3). Reactions of 4-sulfanyl-2-phenyl-6H-1,3-thiazin-6-one with ammonia, amines, and difunctional N-centered nucleophiles involve cleavage of the C6-S bond in the thiazine ring and subsequent recyclization of linear intermediates to pyrimidines and diazole derivatives.
The structure of the isolated compounds was confiirmed by 1H and 13C NMR, IR, and UV spectra. 相似文献
14.
N-(1,3-Thiazol-5(4H)-ylidene)amines via 1,3-Dipolar Cycloaddition of Azides and 1,3-Thiazol-5(4H)-thiones Organic azides 5 and 4,4-dimethyl-2-phenyl-1,3-thiazol-5(4H)-thione ( 2 ) in toluene at 90° react to give the corresponding N-(1,3-thiazol-5(4H)-ylidene)amines (= 1,3-thiazol-5(4H)-imines) 6 in good yield (Table). A reaction mechanism for the formation of these scarcely investigated thiazole derivatives is formulated in Scheme 3: 1,3-Dipolar azide cycloaddition onto the C?S group of 2 leads to the 1:1 adduct C . Successive elimination of N2 and S yields 6 , probably via an intermediate thiaziridine E . 相似文献
15.
A. N. Skvortsov V. M. Uvarov D. A. de Vekki E. P. Studentsov N. K. Skvortsov 《Russian Journal of General Chemistry》2010,80(10):2007-2021
2-Aryl- and 2-furyl-4-carboxy-1,3-thiazolidines were synthesized. Their spectral properties were studied, and conformational
analysis was performed. It was shown that they exist in solution as an equilibrium of neutral and zwitter-ion forms. The influence
of the nature of substitutents and of their location in a benzene ring of thiazolidines as ligands of rhodium complexes on
acetophenone hydrosilylation with diphenylsilane was examined. Thiazolidines containing donor substituents in the para-position of the benzene ring were found to be the most effective; maximal asymmetrical induction (55% ee) was reached in the presence of 2-(4-methoxyphenyl)-4-carboxy-1,3-thiazolidine. 相似文献
16.
Dmitrieva L. L. Nikitina L. P. Albanov A. I. Sarapulova G. I. Nedolya N. A. Brandsma L. 《Russian Journal of Organic Chemistry》2004,40(2):178-187
Reactions of allyl and 2-(vinyloxy)ethyl isothiocyanates with alyylmagnesium bromide (THF-Et2O, 20-30°C, 1-3 h) after hydrolysis or alkylation of adducts afforded respectively N-allyl- and N-[2-(vinyloxy)ethyl]-3-butenethioamides or N-allyl- and N-[2-(vinyloxy)ethyl]-1-(methylmercapto)-3-buten-1-imines. The reaction carried out in ethyl ether yielded instead of Nt-allyl-3-butenethioamide its isomer N-allyl-2-butenethioamide that cleanly isomerized in the system KOH-DMSOH2O into N-(1-propenyl)-2-butenethioamide. N-[2-(vinyloxy)ethyl]-3-butenethioamide suffers a prototropic rearrangement into N-[2-(vinyloxy)ethyl]-2-butenethioamide only in the system 相似文献
17.
The 1,3-dipolar addition of acetylenedicarboxylic esters (IX and X) to 2-methyl-4-phenyl-quinazoline 3-oxide (VIII) in benzene/methanol and benzene/ethanol, respectively, gives the esters XI and XII of 3-amino-3-phenyl-2-(2-acetamidophenyl)-acrylic acid as main products and the esters XIII and XIV of 2-methyl-4-phenyl-5H-benzo[d][1,3]diazepin-5-carboxylic acid as by-products. The constitutions of XI and XII are elucidated by acid hydrolysis to the 2-phenylindole-3-carboxylic esters VI and VII, respectively, and by ozonolysis of XII to give benzamide and ethyl o-acetamido-mandelate (IV). The alkaline hydrolysis of XI or XII gives the enamine derivative XVIII, which is hydrolysed by acid to oxindole and benzoic acid. The structure elucidation of XIII and XIV is based on spectroscopic data together with thc formation of XV by alkaline hydrolysis. Mechanisms arc proposed for the reaction paths. 相似文献
18.
M. D. Khanova R. M. Sultanova S. L. Khursan V. A. Dokichev Yu. V. Tomilov 《Russian Chemical Bulletin》2006,55(8):1464-1469
Methoxycarbonylcarbene generated by catalytic decomposition of methyl diazoacetate in the presence of Rh2(OAc)4, is regioselectively inserted into the C(2)-O bond of 3-alkyl-2-phenyl-1,3-oxazolidines and into the C(2)-S bond of 2-phenyl-1,3-oxathiolane.
Study by the competitive reaction method demonstrated that the relative reactivity toward the insertion of the methoxycarbonylcarbene
fragment into the C-heteroatom bond increases in the series of 1,3-dioxolane, 1,3-oxazolidine, and 1,3-oxathiolane.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1411–1415, August, 2006. 相似文献
19.
The Diels-Alder reaction of 4,5-dimethylene-2,2-diphenyldioxolane with diethyl azodicar-boxylate and 4-phenyl-1,2,4-triazoline-3,5-dione was investigated. Reduction of the resultant adducts followed by hydrolysis provided hexahydro-4,5-dihydroxy-1,2-pyridazine dicarboxylic acid diethylester and 1,3,5,6,7,8-hexahydro-6,7-dihydroxy-2-pheny 1-2H-s-triazolo[1,2-α ]pyrida-zine-1,3-dione. 相似文献
20.
Karl-Richard Meier Anthony Linden Heinz Heimgartner Grzegorz Mlosto 《Helvetica chimica acta》1997,80(4):1190-1204
1,3-Dipolar Cycloadditions of a Carhonyl-ylide with 1,3-Thiazole-5(4H)-thiones and Thioketones Inp-xylene at 150°, 3-phenyloxirane-2,2-dicarbonitrile ( 4b ) and 2-phenyl-3-thia-1-azaspiro[4.4]non-1-ene-4-thione ( 1a ) gave the three 1:1 adduets trans- 3a , cis- 3a , and 13a in 61, 21, and 3% yield, respectively (Scheme 3). The stereoisomers trans- 3a and cis- 3a are the products of a regioselective 1,3-dipolar cycloaddition of carbonylylide 2b , generated thermally by an electrocyclic ring opening of 4b (Scheme 6), and the C?S group of 1a . Surprisingly, 13a proved not to be a regioisomeric cycloadduct of 1a and 2b , but an isomer formed via cleavage of the O? C(3) bond of the oxirane 4b . A reaction mechanism rationalizing the formation of 13a is proposed in Scheme 6. Analogous results were obtained from the reaction of 4b and 4,4-dimethyl-2-phenyl-1,3-thiazole-5 (4H)-thione ( 1b , Scheme 3). The thermolysis of 4b in p-xylene at 130° in the presence of adamantine–thione ( 10 ) led to two isomeric 1:1 adducts 15 and 16 in a ratio of ca. 2:1, however, in low yield (Scheme 4). Most likely the products are again formed viathe two competing reaction mechanisms depicted in Scheme 6. The analogous reactions of 4b with 2,2,4,4-tetramethylcyclobutane-1,3-thione ( 11 ) and 9H-xanthene-9-thione ( 12 ) yielded a single 1:1 adduct in each case (Schemes). In the former case, spirocyclic 1,3-oxathiolane 17 , the product of the 1,3-dipolar cycloaddition with 2a corresponding to 3a , was isolated in only 11 % yield. It is remarkable that no 2:1 adduct was formed even in the presence of an excess of 4b. In contrast, 4b and 12 reacted smoothly to give 18 in 81 % yield; no cycloadduct of the carbonylylide 2a could be detected. The structures of cis- 3a , 13a , 15 , and 18 , as well as the structure of 14 , which is a derivative of trans- 3a , have been established by X-ray crystallography (Figs. 1–3, Table). 相似文献