- Urea Cyclisation Reaction Studies
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Synthetic approaches of N-α-hydroxyalkyl amides or urea derivatives are described. In particularly, a new 1,4,6-oxadiazocine-2,5,8-trione was obtained by condensation of glyoxylic acid on urea derivatives in acidic catalysis condition.
- Niddam, Valerie,Medou, Martial,Dessolin, Jean,Trabaud, Carole,Camplo, Michel,Kraus, Jean-Louis
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- Method for preparing 3,3-dimethyl-2-oxo-butyric acid
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The invention relates to the technical field of chemical engineering, and discloses a method for preparing 3,3-dimethyl-2-oxo-butyric acid. The method comprises the following steps: (1) carrying out acontact reaction on oxalyl chloride and N,N'-diphenyl urea to obtain 1,3-diphenyl-2,4,5-imidazoline triketone; (2) enabling the 1,3-diphenyl-2,4,5-imidazoline triketone to react with a Grignard reagent containing tert-butyl to obtain 5-tert-butyl-5-hydroxy-1,3-diphenyl-2,4-imidazolinedione; and (3) carrying out a hydrolysis reaction on the 5-tert-butyl-5-hydroxy-1,3-diphenyl-2,4-imidazolinedione,and acidifying a product obtained after the hydrolysis reaction to obtain the 3,3-dimethyl-2-oxo-butyric acid. The method has the advantages of environmental protection and high efficiency.
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Paragraph 0041-0043; 0048-0050; 0055-0056; 0059-0060
(2020/06/16)
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- Orthoamides and iminium salts LXXIV [1]. Reactions of N,N,N',N'- Tetramethyl-chloroformamidiniumChloride with metals
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N,N,N',N'-Tetramethyl-formamidinium chloride (2a) reacts with elemental sodium in various solvents to give N,N,N',N',N'',N''-hexamethyl-guanidinium chloride (4a). The reaction of 2a with potassium affords N,N,N',N',N'',N'',N''', N'''-octamethyl-oxamidinium dichloride (3a). From the reaction of 2a with magnesium in different solvents in general result mixtures of the salts 4a, 3a and N,N,N',N'-tetramethyl-formamidinium chloride (10a). The composition of these mixtures depends on the solvent and the reaction temperature. Similar results are obtained, when a zinc'copper couple is used instead of magnesium. Very likely from 2a and magnesium or zinc, respectively, organometallic intermediates 11, 12 are formed which could be trapped by aromatic aldehydes and phenylisocyanate. The salt 2a can be reductively coupled by a low-valent titanium reagent to give the oxamidinium salt 3a.
- Kantlehner, Willi,Aichholz, Reiner,Karl, Martin
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experimental part
p. 305 - 319
(2012/07/13)
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- Diphenylparabanic acid as a synthon for the synthesis of α-diketones and α-ketocarboxylic acids
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Diphenylparabanic acid was found to react with >2 equiv of organolithiums at -78 °C to effectively give the corresponding symmetrical α-diketones. However, upon treatment with 1 equiv of organolithium, the parabanic acid gave mainly 5-substituted 5-hydroxyimidazolidine-2,4-diones. On the other hand, Grignard reagents were less reactive toward the parabanic acid at low temperature, and selectively gave the corresponding 5- hydroxyimidazolidine-2,4-diones even if more than 1 equiv of the reagents was used. A tandem process in which the parabanic acid was first reacted with a Grignard reagent and then reacted in one-pot with an organolithium effectively gave the unsymmetrical α-diketone. 5-Substituted 5-hydroxyimidazolidine-2, 4-diones were useful as versatile precursors for preparing α- ketocarboxylic acids as well as unsymmetrical α-diketones.
- Watanabe, Nobuko,Hamano, Mitsutaka,Todaka, Shota,Asaeda, Takahiro,Ijuin, Hisako K.,Matsumoto, Masakatsu
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experimental part
p. 632 - 639
(2012/03/22)
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- Dibutyltin oxide catalyzed aminolysis of oxalate to carbamate, oxamate and derivatives of imidazolidine trione
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Catalytic aminolysis of oxalates by simple and substituted ureas has been shown to give carbamates, oxamates and derivatives of imidazolidine trione. Various substituted ureas and oxalates were screened to verify the applicability of the protocol. The rol
- Kunde, Lalita B.,Kalyani, Vishwanath S.,Gupte, Sunil P.
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experimental part
p. 402 - 407
(2010/08/06)
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- Manganese-catalyzed synthesis of hydantoin derivatives from terminal alkynes and isocyanates
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Hydantoin derivatives were obtained by the reactions of terminal alkynes with isocyanates in the presence of a catalytic amount of a manganese complex, MnBr(CO)5. This reaction also proceeded using a rhenium complex, Re2(CO)10, or an iron complex, Fe(CO)5, as a catalyst. Copyright
- Kuninobu, Yoichiro,Kikuchi, Kou,Takai, Kazuhiko
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p. 740 - 741
(2008/12/21)
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- Generation and Reactivity of N,N-Dimethylaminobenzotriazolylcarbene a New Nucleophilic Carbene
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N,N-Dimethylaminobenzotriazolylcarbene (5) reacted with phenyl isocyanate in a [1+2+2] cycloaddition and then with nucleophiles to generate various hydantoins 10 in a one-pot procedure. It was also found that this novel carbene reacted with trans-dibenzoylethylene (11) in a [1+4] cycloaddition, generating 2-dimethylamino-3-benzoyl-5-pbenylfuran (13) and 2-phenyl-3-[benzotriazol-1-y1]-4-benzoylfuran (14) whose structures were confirmed by 1H-13C long range correlations as well as the structure of furan 14 being confirmed by X-ray crystallography.
- Katritzky, Alan R.,Cheng, Dai,Leeming, Peter,Ghiviriga, Ion,Hartshorn, Chris M.,Steel, Peter J.
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p. 1935 - 1941
(2007/10/03)
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- ESR-Untersuchungen an Thioamiden, 8. Radikalanionen der Imidazolidintrione, Piperazindione, Piperazintetraone und Chinoxalindione sowie ihrer Schwefel-Analoga.
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Cyclische Oxamid-Derivate vom Typ des Imidazolidin-4,5-dions, Piperazin-2,3-dions, Piperazin-2,3,5,6-tetraons und Chinoxalin-2,3-dions sowie Thio-Analoga und mit 2H, 13C oder 15N markierte Vertreter werden dargestellt und durch in-situ-Elektroreduktion in die entsprechenden Radikalanionen uebergefuehrt.Aus deren isotropen und anisotropen ESR-Spektren sowie einer Analyse der Linienbreite und Linienform wird die Spindichteverteilung ermittelt und anhand MO-theoretisch berechneter Werte diskutiert.
- Brix, Peter,Voss, Juergen
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p. 2218 - 2280
(2007/10/02)
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- On the Reaction of Oxalic Amidines with Carbonic Acid Derived Heterocumulenes to Imidazolidine-Derivatives
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A useful synthetic route to nonsymmetric derivatives of imidazolidine (derivatives of parabanic acid) is demonstrated by the reaction of tetraarylated oxalic amidines 1 with different alkyl- and aryl substituted isothiocyanates 4, isoselenocyanates 31, and carbodiimides 30.Acylisothiocyanates 9 react differently leading to a mixture of three cycloacylation products 12, 13 and 14.Silylated heterocumulenes such as 25 and 26 react with 1 to give 28 and 29 transsilylation.Based on the 13C-n.m.r. spectroscopic investigation of the reaction between 1a and methyl isothiocyanate and phenyl isothiocyanate respectively a mechanism is proposed.
- Beckert, R.,Gruner, M.
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- Extremely Reactive C=C Double Bonds, VI. - Tris(methylphenylamino)methane - The Chemistry of Orthoamides
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Reactions of the title compound 2 with sulfur, selenium, thiophenol, malononitrile, 1,3-indanedione, fluorenone hydrazone, phenylmagnesium bromide, bromine, thioacetic acid, N,N'-diphenylurea, oxalyl chloride, 9,9-dichloroxanthene, phenyl isocyanate, and stilbene dibromide are described and the mechanisms are discussed.The catalytic influence of 2 on the decomposition of 9-diazofluorene in xylene and mesitylene is discussed.
- Schoenberg, Alexander,Singer, Erich,Stephan, Werner
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p. 1581 - 1588
(2007/10/02)
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- Reaction of Oxalyl Chloride and Alkyloxalyl Chlorides with Isocyanates and Isothiocyanates
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Alkyl and aryl isothiocyanates react with oxalyl chloride (1) on both double bonds of the heterocumulene to yield 3-alkyl- or 3-aryl-2,2-dichlorothiazolidine-4,5-diones 2.The two chlorines in these novel orthocarbonic acid derivatives are readily exchanged by alkoxy groups to yield 2,2-dialkoxythiazolidine-4,5-diones 3; hydrolysis of 2a (R=CH3) gave 3-methylthiazolidine-2,4,5-trione. 3-Substituted 5,5-dichlorooxazolidine-2,4-diones 8 and 5-chloro-5-alkoxyoxazolidine-2,4-diones 13 are obtained on reacting alkyl, aryl, and benzyl isocyanates with 1 and alkyloxalyl chloride, respectively.Structure assignment to these novel cycloadducts is based on IR, 1H NMR, and 13C NMR spectroscopic as well as X-ray crystallographic analysis.Formation of 8 and 13 is a stepwise process involving labile acyclic intermediates 7 and 12.The cyclizations to 8 and 13 take place only on the C=N bond of the isocyanate group.
- Richter, R.,Stuber, F. A.,Tucker, B.
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p. 3675 - 3681
(2007/10/02)
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- Process for the production of imidazolidine triones
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A process for the production of imidazolidine triones by reacting optionally masked iso(thio)cyanates with oxalic acid mono esters.
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- Derivatives of Imidazolidines from Oxalic Amidines
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Tetraarylsubstituted oxalic amidines 1 react with acyl chlorides, phosgene, thiophosgene, chlorocarbonylsulfenylchloride, isocyaniddichlorides, and N-aroyl-1-chlorothio-formimidoylchlorides 7 to give the corresponding 5-membered heterocycles 3,4,5 and 8.Isocyanates 9 and isothiocyanates 10 react with oxalic amidines to yield imidazolidines 11, 12 and ureas 13, 14.Hydrolysis of 3-5, 8, 11, 12 leads to the corresponding oxo compounds 15, 16.
- Beckert, R.,Mayer, R.
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p. 227 - 236
(2007/10/02)
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- Orthoamides, XXXVII. Reactions of 2,2-Bis(dialkylamino)acetonitriles and 2-(Dialkylamino)-2-methoxyacetonitriles with Isocyanates
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The nitriles 1a - c react with isocyanates to give the parabanic acid aminals 10a - g.By alcoholysis of the aminals 10 the parabanic acid O,N-acetals 12a - d are prepared.Compounds of type 12 are also accessible from the amide acetal 3a and 5-imino-2,4-imidazolidinediones 13.By means of the 14C-labelled nitrile 22 it is shown that the C-5 atom of the imidazolidine system in 10 arises from the nitrile group of 1.Hence, the reactions yielding the compounds 10 are mechanistically not related with the reactions of the amide acetals 3 with isocyanates giving parabanic acid O,N-acetals 7.From the complex product mixtures, formed in the reaction of the nitriles 2 with isocyanates, the parabanic acid O,N-acetals 7a - c and the 5-imino-2,4-imidazolidinediones 13a,c are isolated.
- Kantlehner, Willi,Haug, Erwin,Isak, Heinz,Schulz, Wolfgang,Hippich, Silvin,et al.
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p. 1721 - 1732
(2007/10/02)
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- CLEAVAGE AND SOME MODIFICATIONS OF THE 7-AMIDE GROUP OF THE CEPHAMYCINS
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The cleavage and some modifications of the 7-amide group of cephamycins are described.Cephamycin derivatives 16b, c which were synthesized from the naturally occuring cephamycin C (16a) were converted to the corresponding oxamic acid derivatives 17a, e respectively by the reaction with oxalyl chloride and successive treatment with water.The reaction of the oxamic acid 17a with diphenylcarbodiimide gave 7-aminocephamycinoic acid (7-ACMA) benzhydryl ester (21a) which was further converted to cefoxitin (21c).These compounds 17a, b, c, d, e, f thus obtained from cephamycin C appear to be favorable intermediates for the syntheses of cephamycin analogues such as cefmetazole (28c).
- Shiozaki, Masao,Ishida, Noboru,Iino, Kimio,Hiraoka, Tetsuo
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p. 2735 - 2740
(2007/10/02)
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- On the Reaction of Bis(dimethylamino)acetonitrile with Phenylisocyanate
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Bis(dimethylamino)acetonitrile (1) reacts with phenylisocyanate to yiield the imidazolidinedione 2, as confirmed by X-ray structure analysis.The mechanism of formation of 2 is discussed.
- Seckinger, Karl
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p. 1958 - 1959
(2007/10/02)
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