5616-32-0Relevant academic research and scientific papers
High-yielding automated convergent synthesis of no-carrier-added [11C-carbonyl]-labeled amino acids using the strecker reaction
Xing, Junhao,Brooks, Allen F.,Fink, Dylan,Zhang, Huibin,Piert, Morand R.,Scott, Peter J.H.,Shao, Xia
supporting information, p. 371 - 375 (2017/02/10)
A new variant of the Strecker synthesis using no-carrier-added [11C]cyanide for the synthesis of radiolabeled amino acids is described. The protocol is fully automated using a radiochemistry synthesis module and applied to the production of a number of new PET radiotracers. [11C-Carbonyl]sarcosine, [11C-carbonyl]methionine, [11C-carbonyl]-N-phenylglycine, and [11C-carbonyl]glycine are all synthesized in moderate to good radiochemical yields. The synthesis of [11C-carbon-yl]sarcosine has been validated for production of doses for clinical use, and preliminary evaluation of the new radiotracer in PC3 tumor-bearing mice is also reported.
Process for the preparation of creatine water (by machine translation)
-
Paragraph 0041; 0042, (2016/10/07)
The invention discloses a preparation method of creatine monohydrate, and provides the preparation method of the creatine monohydrate. The method comprises the following steps: step 1, carrying out a nucleophilic substitution reaction on a glycolonitrile aqueous solution and a methylamine aqueous solution for 1 to 6 hours at a temperature of 10 DEG C to 40 DEG C so as to generate methylamino acetonitrile; step 2, carrying out a hydrolysis reaction on the methylamino acetonitrile reaction liquid obtained in the step 1 for 2 to 6 hours at the temperature of 60 DEG C to 80 DEG C and in the presence of sodium hydroxide so as to obtain a sodium sarcosinate aqueous solution; step 3, regulating pH to 9 to 12 and carrying out a condensation reaction on the sodium sarcosinate aqueous solution and the cyanamide for 1 to 6 hours at the temperature of 50 DEG C to 90 DEG C so as to obtain the creatine monohydrate. The method is moderate in reaction condition, less in byproduct, high in yield and suitable for industrial production. The structure of the creatine monohydrate is as shown in the specification.
Microwave-assisted solvent-free intramolecular 1,3-dipolar cycloaddition reactions leading to hexahydrochromeno[4,3-b]pyrroles: scope and limitations
Pospí?il, Ji?í,Potá?ek, Milan
, p. 337 - 346 (2007/10/03)
We report the microwave-assisted solvent-free synthesis of hexahydrochromeno[4,3-b]pyrroles. Intramolecular 1,3-dipolar cycloadditions proceed under these conditions within 15-40 min in 16-84% yields. An influence of the microwave irradiation upon various [3+2] cycloaddition reaction intermediates was studied. Additionally, a scope and limitations of these reactions including an influence of the dipolarophile geometry upon the cycloaddition selectivity and steric demands of the dipole upon its reactivity were also disclosed. These observations led us to postulate a preferable transition state of the reaction. Finally, an influence of the microwave irradiation to the isomerization of activated olefins was also described.
Chemistry of α-Amino Nitriles. Exploratory Experiments on Thermal Reactions of α-Amino Nitriles
Xiang, Yi-Bin,Drenkard, Susanne,Baumann, Karl,Hickey, Deirdre,Eschenmoser, Albert
, p. 2209 - 2250 (2007/10/02)
The paper extends a previously published report on chemical properties of α-amino nitriles and of members of the C3H4N2 ensemble (Scheme 1) as observed in experiments carried out under non-aqueous conditions.The reactions investigated and the observations made are summarized in some detail in the English footnotes (*) referring to Schemes 1-17 and Fig. 1.
TiCl4 induced N-methyleneamine equivalents: A new route to aminoacetonitriles
Ha,Nam,Park
, p. 155 - 160 (2007/10/02)
TiCl4 induced N-methyleneamine equivalents from hexahydro-1,3,5-triazines or N-(methoxymethyl)amines were reacted with trimethylsilyl cyanide to give aminoacetonitriles in 40-90% yield.
Total Synthesis of Marine Mercaptohistidines: Ovothiols A, B, and C
Holler, Tod P.,Ruan, Fuqiang,Spaltenstein, Andreas,Hopkins, Paul B.
, p. 4570 - 4575 (2007/10/02)
Syntheses of ovothiols A and C in optically active form and ovothiols A and B in racemic form are reported.In all cases, synthesis of an S-protected mercaptoimidazole is followed by elaboration of an amino acid side chain.
SYNTHESE D'IMINES LINEAIRES NON-STABILISEES PAR REACTIONS GAZ-SOLIDE SOUS VIDE(1).
Guillemin, Jean-Claude,Denis, Jean-Marc
, p. 4431 - 4446 (2007/10/02)
Unstabilized imines are synthetized in gram-scale by vacuum dehydrochlorination of N-chloroalkylamines and by vacuum dehydrocyanation of α-aminonitriles on solid base.All the new compounds are characterized at low temperature by 1H, 13C NMR and IR spectroscopy.
KINETICS AND MECHANISM OF BASE-CATALYZED CYCLIZATION OF SUBSTITUTED AMIDES AND NITRILES OF HYDANTOIC ACID
Machacek, Vladimir,Svobodova, Gabriela,Sterba, Vojeslav
, p. 140 - 155 (2007/10/02)
Rates of base-catalyzed cyclizations of 8 substituted derivatives of hydantoic acid amide type R3-NH(5)-CO(4)-NR2(3)-CH2(2)-CO(1)-NHR1 and 9 nitriles type R3-NH(5)-CO(4)-NR2(3)-CHR1(2)-CN have been measured in aqueous and methanolic media.The cyclization of the amides in aqueous medium is also accompanied by hydrolysis of the hydantoins formed.In some cases the hydrolysis rate constant is greater than the corresponding cyclization reaction rate constant.With the least reactive amides, the cyclization is also accompanied by hydrolysis of the amide group.The ra te of the cyclization reactions in water is higher than that in methanol (at the same concentration of the lyate ions) by the factor of 10 - 100.Substitution of hydrogen at 3 and 5 positions by methyl or phenyl groups causes an acceleration of the cyclization reaction, whereas a substitution in the amide group causes a considerable retardation.The greatest acceleration of the cyclization (by as much as 4 orders) is caused by introduction of phenyl group to the N(5) position, which is due to a substantial increase of concentration of the reactive anion.
A New Synthesis of 4- and 5-Imidazolethiols
Spaltenstein, Andreas,Holler, Tod P.,Hopkins, Paul B.
, p. 2977 - 2979 (2007/10/02)
Several examples of a new, mild, and regiocontrolled multistep synthesis of multiply substituted 4- and 5-imidazolethiols are reported.The key step involves a dehydration/cyclization promoted by trimethylsilyl triflate and triethylamine
