7150-63-2Relevant academic research and scientific papers
Rhodanine-based tau aggregation inhibitors in cell models of tauopathy
Bulic, Bruno,Pickhardt, Marcus,Khlistunova, Inna,Biernat, Jacek,Mandelkow, Eva-Maria,Mandelkow, Eckhard,Waldmann, Herbert
, p. 9215 - 9219 (2008/12/22)
Breaking up the crowd: The pathological aggregation of tau protein correlates closely with the progression of Alzheimer's disease. Rhodanine-based inhibitors of tau aggregation (e.g. 1) have been identified, and it has been shown that tau aggregation in a
Pd(OAc)2-catalyzed carbonylation of amines
Orito, Kazuhiko,Miyazawa, Mamoru,Nakamura, Takatoshi,Horibata, Akiyoshi,Ushito, Harumi,Nagasaki, Hideo,Yuguchi, Motoki,Yamashita, Satoshi,Yamazaki, Tetsuro,Tokuda, Masao
, p. 5951 - 5958 (2007/10/03)
A phosphine-free catalytic system [Pd(OAc)2-Cu(OAc) 2-air] induced a substrate-specific carbonylation of amines in boiling toluene under CO gas (1 atm). Symmetrical N,N′-dialkylureas were obtained by the carbonylation of primary amines. N,N,N′-Trialkylureas were selectively formed by addition of a secondary amine to the above reaction vessel. Secondary amines did not give tetraalkylureas. However, dialkylamines with a phenyl group on their alkyl chains, such as N-monoalkylated benzylic amine or phenethylamine derivatives, underwent a direct aromatic carbonylation to afford five- or six-membered benzolactams. In the carbonylation, the chelation effect or steric repulsion between Pd(II) and the meta-substituent in the ortho-palladation and the ring sizes of cyclopalladation products that were formed prior to carbonylation were found to generate good site selectivity and increase the reaction rate. In contrast, carbonylation of ω- arylalkylamines with a hydroxyl group gave neither ureas nor benzolactams but instead produced 1,3-oxazolidinones smoothly. Hydrochlorides of amines also underwent carbonylation to afford the corresponding amides under the conditions used. This procedure made it possible to prepare ureas of amino acid esters and N-alkylcarbamates in practical yields.
A convenient synthesis of symmetrical N,N′-dialkylureas by the reactions of 4-chloro-5H-1,2,3-dithiazol-5-one with alkylamines
Chang, Yong-Goo,Lee, Hyi-Seung,Kim, Kyongtae
, p. 8197 - 8200 (2007/10/03)
Treatment of 4-chloro-5H-1,2,3-dithiazol-5-one with primary and secondary alkylamines (>2 equiv.) in CH2Cl2 at rt afforded symmetrical N,N′-disubstituted ureas in moderate to good yields. Similarly, the reactions with amino acid ester hydrochlorides in the presence of Et3N (>3 equiv.) under the same conditions gave symmetrical ureas.
Synthesis of N,N′-carbonyl-bis-amino acids and N,N′-carbonyl-bis-peptides
Izdebski,Pawlak
, p. 1066 - 1074 (2007/10/03)
A new method for the preparation of N,N′-carbonyl-bis-amino acid esters by reaction of bis(4-nitrophenyl)carbonate with amino acid esters is described. When the carbonate reacts with two equivalents of a peptide ester, N,N′-carbonyl-bis(peptide ester) is obtained but, a hydantoin derivative is formed as a side product. The hydantoin derivative is a major product, when equimolar amounts are allowed to react. Usefulness of this method for preparation of larger N,N′carbonyl-bis-peptides is demonstrated by the synthesis of the respective product from C-terminal hexapeptide of Substance P linked to the Merrifield resin.
An approach to the design of molecular solids. Strategies for controlling the assembly of molecules into two-dimensional layered structures
Chang, Yuh-Loo,West, Mary-Ann,Fowler, Frank W.,Lauher, Joseph W.
, p. 5991 - 6000 (2007/10/02)
A design strategy for the synthesis of molecular crystals containing two-dimensional layers is formulated and demonstrated by the synthesis and structure determination of a series of dicarboxylic acid urea derivatives. The design strategy is based upon th
LATENT INHIBITORS. PART 4. IRREVERSIBLE INHIBITION OF DIHYDRO-OROTATE DEHYDROGENASE BY HYDANTOINS DERIVED FROM AMINO ACIDS
Buntain, Ian G.,Suckling, Colin J.,Wood, Hamish C. S.
, p. 3175 - 3182 (2007/10/02)
Hydantoins and ureas derived from α-amino acids are shown to interact with dihydro-orotate dehydrogenase from Clostridium (Zymobacterium) oroticum, chiefly as weak competitive inhibitors but that the hydantoin derived from phenylalanine, 5-benzyl-3-(1-car
MECHANISM OF BASE-CATALYZED CYCLIZATION OF ETHYL N-(SUBSTITUTED AMINOCARBONYL)GLYCINATES
Mindl, Jaromir,Sterba, Vojeslav
, p. 156 - 161 (2007/10/02)
The cyclization rate constants have been measured of substituted ethyl N-(phenylaminocarbonyl)-, N-(alkylaminocarbonyl)-, and N-(phenylaminothiocarbonyl)glycinates RNHCXNHCH2CO2C2H5 (X=O,S).Logarithms of these constants increase with decreasing basicity of the amines down to the value of pKa(RNH2) = 5.5.The rate-limiting step of the reaction is formation of the tetrahedral intermediate.With ethyl N-(phenylaminocarbonyl)glycinates (whose pKa(RNH2) values are higher) this dependence, on the contrary, slightly decreases, and the acid-catalyzed splitting off of ethoxy group from the cyclic intermediate becomes rate-li miting.The cyclization rate of a series of ethyl N-(phenylaminothiocarbonyl)glycinates is practically independent of the pKa(RNH2) values, the change in the rate limiting step would take place at pH about 9.
