- Synthesis and properties of chiral internally branched PAMAM-dendrimers
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Improved synthetic methodology for the synthesis of internally branched chiral poly(amidoamine) (PAMAM) dendrons and dendrimers has been developed and the compounds have been characterized by NMR spectroscopy, IR spectroscopy, and optical rotation measurements. The dendrons and dendrimers show increased degree of internal hydrogen bonding upon increasing generation and the presence of different types of amide-protons in the compounds is indicative of the existence of a tertiary structure in these PAMAM-dendrimers.
- Petersen, Johannes F.,Tortzen, Christian G.,Pittelkow, Michael,Christensen, J?rn B.
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- Synthesis of a water-soluble chiral NMR shift reagent: (S)-PDTA
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A five-step synthesis of the water-soluble chiral polydentate ligand, (S)-PDTA [(S)-PDTA = N,N,N′,N′-tetrakis[(hydroxycarbonyl)methyl]-(S)-1,2-diaminopropane] starting from l-alanine has been worked out, via steps with retention of chirality. Total yield is 50.7% (average of ~88% for each step), while published methods report 33.4% total yield over four steps.
- Florini, Nicola,Arnaud, Gaelle F.,Konya, Balint,Zucchi, Claudia,Palyi, Gyula
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- Preparation method of dexrazoxane
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The invention aims to provide a simple and efficient preparation method of dexrazoxane. According to the present invention, 1, 2-propane diamine is adopted as an initial raw material, splitting is performed to obtain hydrochloride of (S)-1, 2-propane diamine, the hydrochloride and bromoacetate are subjected to condensation to prepare (S)-1, 2-diaminopropane-tetraacetate, amide is adopted as an ammonia source, and dexrazoxane is finally prepared. The method has advantages of high yield, mild reaction conditions, easy operation and less environmental pollution, and is beneficial to large-scale industrial production.
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Paragraph 0023-0024
(2021/11/14)
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- Dexrazoxane preparation method
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The invention belongs to the field of drug synthesis, and provides a completely-new dexrazoxane preparation method, which comprises: carrying out a reaction on (S)-1,2-propanediamine ditartrate splitby using inexpensive and easily-available (+/-)-1,2-propanediamine as a starting raw material and using D-(-)-tartaric acid as a splitting agent and potassium chloride to obtain (S)-1,2-propanediaminedihydrochloride, carrying out condensation on the (S)-1,2-propanediamine dihydrochloride and chloroacetic acid to prepare (S)-N,N,N',N'-1,2-propanediaminetetraacetic acid, and finally carrying out cyclization to obtain dexrazoxane, wherein the total yield is 38.3%. According to the present invention, the route has advantages of simple reaction step, convenient post-treatment, no requirement of column chromatography separation, good product quality and the like.
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Paragraph 0016-0017; 0020-0021
(2019/07/04)
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- Simplified syntheses of the water-soluble chiral shift reagents Sm-(R)-pdta and Sm-(S)-pdta
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The chiral shift reagents Sm-(R)-pdta and Sm-(S)-pdta, which are based on (R)- or (S)-1,2-diaminopropane-N,N,N′,N′-tetraacetic acid were synthesized from easily accessible compounds in three simple steps, which makes the method suitable for laboratory-scale production. In addition, a new and efficient method for the preparation of pure anhydrous (R)- or (S)-1,2-diaminopropane-N,N,N′,N′-tetraacetic acid was developed.
- Hrubá, Lucie,Budě?ínsky, Milo?,Pícha, Jan,Jirá?ek, Ji?í,Vaněk, Václav
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supporting information
p. 6296 - 6297
(2013/11/06)
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- Asymmetric catalysis of carbon-carbon bond forming reactions using amino acid-derived C1-symmetrical salen ligands
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Four amino acids (alanine, valine, phenylalanine and phenylglycine) have been converted into C1-symmetrical salen ligands and complexed to titanium, vanadium, copper and cobalt. The resulting complexes have been used as asymmetric catalysts for asymmetric cyanohydrin synthesis, asymmetric Strecker reactions, asymmetric synthesis of α-methyl amino acids and asymmetric Darzens condensations. Satisfactory levels of asymmetric induction were obtained from reactions in which the (salen)metal complex acts as a chiral Lewis acid, but low levels of asymmetric induction were obtained from reactions carried out under solid-liquid phase-transfer conditions.
- Belokon, Yuri N.,Hunt, Jamie,North, Michael
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experimental part
p. 2804 - 2815
(2009/06/28)
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- Hydrolysis of cyclic ureas under microwave irradiation: Synthesis and characterization of 7,8-diaminopelargonic acid
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A simple and efficient method for the synthesis of 7,8-diaminopelargonic acid, a key intermediate in the biotin biosynthesis pathway, is reported. The d-desthiobiotin powder was dissolved in concentrated hydrochloric acid, and the solution was exposed to microwave radiation of 2.45 GHz for varying lengths of time ranging from 60 s to 2 min. The product thus obtained was characterized by spectroscopic techniques and confirmed through bioassay. Further, the protocol was extended to the synthesis of several diamines from their corresponding cyclic ureas. The results show that the method is generally applicable and not only accelerates the hydrolysis reaction but also offers excellent yields. Copyright Taylor & Francis Group, LLC.
- Vasanthakumar, Ganga Ramu,Bhor, Vikrant M.,Surolia, Avadhesha
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p. 2633 - 2639
(2008/02/12)
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- A new and facile route for the synthesis of chiral 1,2-diamines and 2,3-diamino acids
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The synthesis of chiral diamines and diamino acids has been achieved from the corresponding N-arylsulfonyl aziridines through reaction with a chiral isocyanate and subsequent hydrolysis of 2-imidazolidinones. The method appears to be general and of wide applicability.
- Nadir, Upender K.,Krishna, R. Vijaya,Singh, Anamika
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p. 479 - 482
(2007/10/03)
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- Enantioselective synthesis of α-amino acids and monosubstituted 1,2- diamines by conjugate addition of 4-phenyl-2-oxazolidinone to nitroalkenes
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The addition of the potassium salt of (R)- or (S)-4-phenyl-2- oxazolidinone to monosubstituted nitroalkenes proceeded with very good diastereoselectivity. Several of the addition products were converted into α-amino acids and monosubstituted 1,2-diamines of high enantiomeric purity.
- Lucet, Denis,Sabelle, Stephane,Kostelitz, Olivier,Le Gall, Thierry,Mioskowski, Charles
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p. 2583 - 2591
(2007/10/03)
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- Manganese complexes of nitrogen-containing macrocyclic ligands effective as catalysts for dismutating superoxide
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The present invention is directed to low molecular weight mimics of superoxide dismutase (SOD) represented by the formula: STR1 wherein R, R', R1, R'1, R2, R'2, R3, R'3, R4, R'4, R5, R'5, R6, R'6, R7, R'7, R8, R'8, R9, and R'9 and X, Y, Z and n are as defined herein, useful as therapeutic agents for inflammatory disease states and disorders, ischemic/reperfusion injury, stroke, atherosclerosis, hypertension and all other conditions of oxidant-induced tissue damage or injury.
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- Methods of preparing manganese complexes of nitrogen-containing macrocyclic ligands
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The present invention is directed to low molecular weight mimics of superoxide dismutase (SOD) represented by the formula: STR1 wherein R, R', R1, R'1, R2, R'2, R3, R'3, R4, R'4, R5, R'5, R6, R'6, R7, R'7, R8, R'8, R9, and R'9 and X, Y, Z and n are as defined herein, useful as therapeutic agents for inflammatory disease states and disorders, ischemic/reperfusion injury, stroke, atherosclerosis, hypertension and all other conditions of oxidant-induced tissue damage or injury.
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- Modified Amino Acids and Peptides. Part 2. A Convenient Conversion of Amino and Peptide Alcohols into Amines.
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A convenient general method for the conversion of N-protected amino and peptide alcohols into amines is described.The hydroxyl group of the alcohols was replaced by an azido group and a substituted amino group after activation through mesylation.Hydrogenation of the N-protected amino azides afforded optically active monoprotected diamines or free 1,2-diamines depending on the N-protecting group.Selective reduction of the azido group in the presence of a benzyloxycarbonyl group was performed in high yield using sodium borohydride in the presence of 10percent palladium on charcoal.
- Kokotos, George,Constantinou-Kokotou, Violetta
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p. 3117 - 3132
(2007/10/02)
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- SYNTHESIS OF 1,2-AMINOAZIDES. CONVERSION TO UNSYMMETRICAL VICINAL DIAMINES BY CATALYTIC HYDROGENATION OR REDUCTIVE ALKYLATION WITH DICHLOROBORANES.
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1,2-aminoazides are easily prepared from 1,2-amino alcohols.Catalytic hydrogenation in the presence of palladium on charcoal or reductive alkylation with dichloroboranes afford with good yields unsymmetrically substituted vicinal diamines.
- Benalil, Aziza,Carboni, Bertrand,Vaultier, Michel
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p. 8177 - 8194
(2007/10/02)
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- Process for preparing bis (3,5-dioxopiperazinyl) alkanes or alkenes
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A process for preparing a compound of the formula (I) STR1 wherein R1 and R2 are individually selected from the group consisting of hydrogen and methyl or R1 and R2 together represent an ethylene bridge group comprising: reacting a diamine of the formula (II) where R1 and R2 are defined as above with formaldehyde and an alkaline metal cyanide at a pH in the range of about 0 to 2 to produce a tetranitrile of the formula (III): hydrating said tetranitrile to yield an acid addition salt of a tetraamide of the formula (IV): where R1 and R2 are defined as in formula (I) and X is an acid anion such as fluoride, chloride, bromide or sulfate but preferably chloride; and reacting said acid addition salt of said tetraamide in a cyclization reaction to yield said compound of the formula (I).
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