- 3-(Triflyloxy)benzynes Enable the Regiocontrolled Cycloaddition of Cyclic Ureas to Synthesize 1,4-Benzodiazepine Derivatives
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A versatile synthesis of 1,4-benzodiazepine derivatives through the reaction of various 3-(trifluoromethanesulfonyloxy)benzynes with N -(p -toluenesulfonyl)imidazolidin-2-ones is reported. This reaction system provides a 1,4-benzodiazepine bearing a trifluoromethanesulfonyloxy group as a single regioisomer among the four possible regioisomers.
- Kaneko, Hideki,Ikawa, Takashi,Yamamoto, Yuta,Arulmozhiraja, Sundaram,Tokiwa, Hiroaki,Akai, Shuji
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supporting information
p. 943 - 948
(2018/02/26)
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- A new general pathway for synthesis of reference compounds of N-terminal valine-isocyanate adducts
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Adducts to Hb could be used as biomarkers to monitor exposure to isocyanates. Particularly useful is the measurement of carbamoylation of N-terminal valines in Hb, after detachment as hydantoins. The synthesis of references from the reactive isocyanates, especially diisocyanates, has been problematic due to side reactions and polymerization of the isocyanate starting material. A simpler, safer, and more general method for the synthesis of valine adducts of isocyanates has been developed using N-[(4-nitrophenyl)-carbamate] valine methylamide (NPCVMA) as the key precursor to adducts of various mono-and diisocyanates of interest. By reacting NPCVMA with a range of isocyanate-related amines, carbamoylated valines are formed without the use of the reactive isocyanates. The carbamoylated products synthesized here were cyclized with good yields of the formed hydantoins. The carbamoylated derivative from phenyl isocyanate also showed quantitative yield in a test with cyclization under the conditions used in blood. This new pathway for the preparation of N-carbamoylated model compounds overcomes the abovementioned problems in the synthesis and is a general and simplified approach, which could make such reference compounds of adducts to N-terminal valine from isocyanates accessible for biomonitoring purposes. The synthesized hydantoins corresponding to adducts from isocyanic acid, methyl isocyanate, phenyl isocyanate, and 2,6-toluene diisocyanate were characterized by LC-MS analysis. The background level of the hydantoin from isocyanic acid in human blood was analyzed with the LC-MS conditions developed.
- Davies, Ronnie,Rydberg, Per,Westberg, Emelie,Motwani, Hitesh V.,Johnstone, Erik,Toernqvist, Margareta
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experimental part
p. 540 - 546
(2011/02/24)
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- New generation of enantiomerically pure N-α-carboxyalkylglycolurils
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The title compounds have been synthesised by the α-ureidoalkylation of (S)-N-carbamoyl-α-amino acids with 1,3-dimethyl- and 1,3-dimethyl-4,5-diphenyl-4,5-dihydroxyimidazolidin-2-ones.
- Baranov, Vladimir V.,Kravchenko, Angelina N.,Belyakov, Pavel A.,Makhova, Nina N.
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- Decomposition of N-(2-chloroethyl)-N-nitrosocarbamoyl amino acid amides
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The chemical decomposition of N-(2-chloroethyl)-N-nitrosocarbamoyl (Q(NO)) prolinamide and valinamide were studied under physiological conditions. The volatile products were identified with GC. Q(NO)-Pro-NH2 gave twice the amount of ethylene glycol and only one-fifth of the 2-chloroethanol produced by Q(NO)-Val-NH2 or BCNU, pointing to different pathways of their decomposition. The carbamoylating activity was also investigated in the presence of cyclohexylamine, and it was found to lead mainly to intramolecular carbamoylation with the formation of hydantoin derivatives.
- Suli-Vargha,Bodi,Meszaros,Medzihradszky
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p. 1492 - 1495
(2007/10/02)
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- Preparation of α-aminothioamides from aldehydes
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The conversion of aldehydes into α-aminonitriles and thence into imidazolidin-4-thiones has been studied.Hydrolysis of the appropriate imidazolidin-4-thiones gave thioamides of nine naturally occuring α-amino acids.The possible pre-biotic significance of these compounds is discussed.
- Paventi, Martino,Edward, John T.
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p. 282 - 289
(2007/10/02)
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