- Sustainable Carboxylation of Diamines with Hydrogen Carbonate
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A protocol for the carboxylation of diamines employing quaternary ammonium hydrogen carbonates as C1 source is presented. The approach is used to obtain industrially relevant bis-O-alkyl carbamates with diverse structural features in very high yield, even on gram scale. The quaternary ammonium salts, formally acting as "transporters" of the carboxylating agent, can be recovered after the reaction, and recycled with high efficiency. Regeneration of the hydrogen carbonates on ion-exchange resin grants excellent atom economy in the process.
- Forte, Gianpiero,Chiarotto, Isabella,Richter, Frank,Trieu, Vinh,Feroci, Marta
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p. 1323 - 1327
(2018/09/21)
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- Deuterated batracylin: Deuterium-hydrogen exchange during synthesis and mass spectral analysis
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Deuterium-labeled analogs of the topoisomerase inhibitor batracylin were prepared for metabolism studies to further its evaluation as an antitumor agent. Established syntheses of unlabeled batracylin were adapted for the preparation of deuterated batracyl
- Seltzman, Herbert H.,Fix, Scott E.,Risbood, Prabhakar
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experimental part
p. 206 - 210
(2012/05/20)
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- New metal complexes of semicarbazones derived from para phenylene diamine of NOO/or NO donor sites and their antimicrobial screening
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THE SYNTHESIS and characterization of new Mn(II). Co(II). Ni(II) and Cu(II) complexes with semicarbazone ligands derived from para phenylene diamine {where L1 = Semicarbazide-4-yl-benzene-4 (2-hydroxybenzalde-hydc semicarbazone) [SBHBS], L
- Saleh,Eid,Khalil,El-Ghamry
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experimental part
p. 337 - 356
(2010/04/02)
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- Nitration of ethyl carbamates of phenylenediamines and aniline
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The methyl and ethyl carbamates of aniline and the diethyl dicarbamates of 1,2-, 1,3-, and 1,4-phenylenediamine were prepared. Nitration of the carbamates gave ring mono-, di-, or trinitro-derivatives in good yield. Copyright Taylor & Francis Group, LLC.
- Davis, Matthew C.
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p. 2079 - 2089
(2008/02/04)
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- A new access to quinazolines from simple anilines
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A new synthetic pathway to quinazolines is described. This new method uses hexamethylenetetramine in TFA and potassium ferricyanide in aqueous ethanolic KOH, starting from simple N-protected anilines. The method affords substituted quinazolines with high
- Chilin, Adriana,Marzaro, Giovanni,Zanatta, Samuele,Barbieri, Vera,Pastorini, Giovanni,Manzini, Paolo,Guiotto, Adriano
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p. 12351 - 12356
(2007/10/03)
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- Preparation and applications of a polymer-supported phosphoryl azide
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A polymer-supported diphenylphosphoryl azide was prepared. This polymer-supported version of DPPA is useful due to its lower toxicity, moisture tolerance and ease of workup after reaction. The synthetic application of this solid-phase reagent was explored by conversion of a variety of carboxylic acids to urethanes and ureas through Curtius rearrangement reactions. Carboxylic acids bearing different functional groups (aromatic, aliphatic and heterocyclic carboxylic acids) were subjected to the reaction. The corresponding products were isolated with satisfactory yields.
- Lu, Yuhua,Taylor, Richard T.
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p. 9267 - 9269
(2007/10/03)
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- Synthesis and cytotoxic activity of conjugates of muramyl and normuramyl dipeptides with batracylin derivatives
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The synthesis of MDP (muramyl dipeptide) or nor-MDP (normuramyl dipeptide) conjugates modified at the peptide part with batracylin (BAT) or batracylin derivatives is described. Batracylin was synthesized by our modified method (Scheme 3). The synthesis of BAT via this modified route now appears to be feasible on a multigram scale. Preliminary screening data obtained at the National Cancer Institute (NCI, Bethesda, MD) have revealed that the conjugates did not expose any cytotoxic activity even at 10-4-10-8 M or μg/mL. During tests performed at Medical University of Gdansk, Poland, two analogues 11c and 11e reduced the proliferation of Ab melanoma cells in vitro compared with batracylin alone (Table 2, Figure 1).
- Dzierzbicka, Krystyna,Trzonkowski, Piotr,Sewerynek, Przemys?aw,My?liwski, Andrzej
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p. 978 - 986
(2007/10/03)
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- Carbon Dioxide as a Phosgene Replacement: Synthesis and Mechanistic Studies of Urethanes from Amines, CO2, and Alkyl Chlorides
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Several carbamate esters were synthesized from amines, carbon dioxide, and alkyl chlorides.The effect of added base on the yield and selectivity of carbamate ester formation was found to be highly important with the use of sterically hindered guanidine bases giving the best results.Relative rate studies were carried out giving the following order of reactivity between carbamate anions in acetonitrile with benzyl chloride giving carbamate esters: Et2NCO2(-) = Bu2NCO2(-) > t-BuNHCO2(-) = CyNHCO2(-) = s-BuNHCO2(-) > PhNHCO2(-) > CyCH2NHCO2(-) = n-octylNHCO2(-) = n-BuNHCO2(-).Rate studies were carried out with the diethyl, s-butyl, phenyl, and n-butyl carbamates and activation parameters were determined to be Et2NCO2(-), ΔH(excit.) = 11.8 kcal/mol, ΔS(excit.) = -33 eu; s-BuNHCO2(-), ΔH(excit.) = 12.8 kcal/mol, ΔS(excit.) = -33 eu; PhNHCO2(-), ΔH(excit.) = 14.3 kcal/mol, ΔS(excit.) = -28 eu; n-BuNHCO2(-), ΔH(excit.) = 23.4 kcal/mol, ΔS(excit.) = -3 eu.The unusual results obtained from the use of n-BuNHCO2(-) prompted further studies which showed that the rate of the reaction was inversely dependent on carbon dioxide pressure (20 psig CO2, k = 4.84E-4 M-1 s-1; 120 psig CO2, k = 1.83E-4 M-1 s-1).Nitrogen NMR spectroscopy indicated, via a labeling study with 15N amines and 13C enriched carbon dioxide, the formation of doubly inserted product from the addition of two carbon dioxides to ethylamine in acetonitrile.
- McGhee, William,Riley, Dennis,Christ, Kevin,Pan, Yi,Parnas, Barry
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p. 2820 - 2830
(2007/10/02)
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- Highly Selective Generation of Urethanes from Amines, Carbon Dioxide and Alkyl Chlorides
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Generation of carbamate anions from either a primary or secondary amine, carbon dioxide and a stoichiometric amount of a pentaalkylguanidine followed by the addition of alkyl chlorides gives high yields of urethanes.
- McGhee, William D.,Pan, Yi,Riley, Dennis P.
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p. 699 - 700
(2007/10/02)
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- Reactions of p-Benzoquinone Diimine Derivatives with N,N-Dimethylanilines
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N,N'-Bisalkoxycarbonyl-p-benzoquinone diimine underwent a thermal addition reaction with N,N-dimethylanilines to form an N-C bond between an imino group and an N-methyl group.Upon irradiation the reaction was accelerated.The reaction did not proceed with N-alkyl substituted anilines other than methyl.
- Miyagi, Yo,Maruyama, Kazuhiro,Kurokawa, Mitsunori,Yoshii, Ayumi
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- Production of urethane compounds
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A process for producing a urethane compound which comprises reacting at least one compound selected from the group consisting of a primary amine, a secondary amine and a urea compound with carbon monoxide and an organic hydroxyl compound in the presence of a catalyst system comprising: (a) at least one member selected from the group consisting of platinum group metals and compounds containing at least one platinum group element; and (b) at least one halogen-containing compound selected from the group consisting of alkali or alkaline earth metal halides, onium halides, compounds capable of forming onium halides in the reaction, oxo acids of halogen atoms and their salts, complex compounds containing halogen ions, organic halides and halogen molecules, in the presence of molecular oxygen and/or an organic nitro compound as an oxidizing agent at a temperature of from about 80° C. to about 300° C. under a pressure of from about 1 Kg/cm2 to about 500 Kg/cm2.
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