- Synthesis of racemic δ,δ-dimethylproline derivatives
-
A versatile methodology for the preparation of racemic δ,δ- dimethylproline derivatives has been developed. Methyl N-Boc-δ,δ- dimethylprolinate was synthesized from a β-amino acid in six steps and 55 % overall yield. The route is amenable to the preparation of a broad range of δ,δ-disubstituted prolines by starting with the adequate β-amino acids. In addition, one of the intermediate compounds in the synthetic route has been used for the preparation of a δ,δ- dimethylproline derivative that is substituted at the β-position with a phenyl group. This has been achieved by coupling phenylboronic acid with a regioselectively generated vinyl triflate followed by a stereoselective hydrogenation. δ,δ-Dimethylproline derivatives have been efficiently synthesized by employing a β-amino acid as the starting material. The methodology is amenable to the preparation of other δ,δ- disubstituted prolines. Copyright
- Rodriguez, Isabel,Calaza, M. Isabel,Cativiela, Carlos
-
p. 1093 - 1099
(2013/03/28)
-
- N,N-Dichloroaminosulfonic acids as novel topical antimicrobial agents
-
2-Dichloroamino-2-methyl-propane-1-sulfonic acid sodium salt (2a), a stable derivative of endogenous N,N-dichlorotaurine (1), has been identified and is under development as a topical antimicrobial agent. Structure-activity relationships of analogs were explored to achieve optimal antimicrobial activity with minimal mammalian toxicity while maintaining the desired stability. All the analogs synthesized showed antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans in the range of 1-128 μg/mL and cytotoxicity against mammalian L929 cells in the range 80-1900 μg/mL.
- Low, Eddy,Nair, Satheesh,Shiau, Timothy,Belisle, Barbara,Debabov, Dmitri,Celeri, Chris,Zuck, Meghan,Najafi, Ron,Georgopapadakou, Nafsika,Jain, Rakesh
-
scheme or table
p. 196 - 198
(2009/05/07)
-
- Quaternary ammonium N,N-dichloroamines as topical, antimicrobial agents
-
A series of backbone modified and sulfonic acid replacement analogs of our topical, clinical candidate (iii) were synthesized. Their antimicrobial activities and aqueous stabilities at pH 4 and pH 7 were determined, and has led us to identify quaternary ammonium N,N-dichloroamines as a new class of topical antimicrobial agents.
- Francavilla, Charles,Low, Eddy,Nair, Satheesh,Kim, Bum,Shiau, Timothy P.,Debabov, Dmitri,Celeri, Chris,Alvarez, Nichole,Houchin, Ashley,Xu, Ping,Najafi, Ron,Jain, Rakesh
-
scheme or table
p. 2731 - 2734
(2010/03/03)
-
- Effective methods for the synthesis of N-methyl β-amino acids from all twenty common α-amino acids using 1,3-oxazolidin-5-ones and 1,3-oxazinan-6-ones
-
N-Methyl β-amino acids are generally required for application in the synthesis of potentially bioactive modified peptides and other oligomers. Previous work highlighted the reductive cleavage of 1,3-oxazolidin-5-ones to synthesise N-methyl α-amino acids. Starting from α-amino acids, two approaches were used to prepare the corresponding N-methyl β-amino acids. First, α-amino acids were converted to N-methyl α-amino acids by the so-called '1,3-oxazolidin-5-one strategy', and these were then homologated by the Arndt-Eistert procedure to afford N-protected N-methyl β-amino acids derived from the 20 common α-amino acids. These compounds were prepared in yields of 23-57% (relative to N-methyl α-amino acid). In a second approach, twelve N-protected α-amino acids could be directly homologated by the Arndt-Eistert procedure, and the resulting β-amino acids were converted to the 1,3-oxazinan-6-ones in 30-45% yield. Finally, reductive cleavage afforded the desired N-methyl β-amino acids in 41-63% yield. One sterically congested β-amino acid, 3-methyl-3-aminobutanoic acid, did give a high yield (95%) of the 1,3-oxazinan-6-one (65), and subsequent reductive cleavage gave the corresponding AIBN-derived N-methyl β-amino acid 61 in 71% yield (Scheme 2). Thus, our protocols allow the ready preparation of all N-methyl β-amino acids derived from the 20 proteinogenic α-amino acids.
- Hughes, Andrew B.,Sleebs, Brad E.
-
p. 2611 - 2637
(2007/10/03)
-
- Synthesis of new β-amino acids via 5-oxazolidinones and the arndt-eistert procedure
-
N-Methyl β-amino acids are potentially useful amino acid derivatives for incorporation in lead peptide therapeutics. The syntheses of five such compounds are presented. Their synthesis via 6-oxazinanones was low yielding. Alternatively, reductive cleavage of a 5-oxazolidinone gave the N-methyl β-amino acid, which was then homologated via an Arndt-Eistert procedure in high yield to give the N-methyl α-amino acid. CSIRO 2005.
- Hughes, Andrew B.,Sleebs, Brad E.
-
p. 778 - 784
(2007/10/03)
-
- COMPOUND INHIBITING DIPEPTIDYL PEPTIDASE IV
-
The invention aims to provide a dipeptidyl peptidase IV inhibitor which is satisfactory in respect of activity, stability and safety and has an excellent action as a pharmaceutical agent. The invention is directed to a compound represented by the following general formula or a pharmaceutically acceptable salt thereof: wherein R1 and R2 each represents hydrogen, an optionally substituted C1-6 alkyl group, or -COOR5 whereupon R5 represents hydrogen or an optionally substituted C1-6 alkyl group, or R1 and R2, together with a carbon atom to which they are bound, represent a 3- to 6-membered cycloalkyl group, R3 represents hydrogen or an optionally substituted C6-10 aryl group, R4 represents a hydrogen or a cyano group, D represents -CONR6-, -CO- or -NR6CO-, R6 represents hydrogen or an optionally substituted C1-6 alkyl group, E represents -(CH2)m- whereupon m is an integer of 1 to 3, -CH2OCH2-, or -SCH2-, n is an integer of 0 to 3, and A represents an optionally substituted bicyclic heterocyclic group or bicyclic hydrocarbon group.
- -
-
Page/Page column 12
(2010/02/14)
-
- A New Route to the Synthesis of Amino Acids through the Mercury Cyclization of Chiral Amidals
-
By means of the mercury cyclization of the unsaturated amidals 3a-e, obtained from the reaction of 1,3,5-tris-hexahydrotriazine (1) and α,β-unsaturated acyl chlorides, diastereomeric mixtures of imidazolidin-4-ones 5-8 and perihydropyrimidin-4-ones 9-10 have been synthesized and easily separated by flash chromatography.The subsequent hydrolysis under acid conditions of the separated heterocycles affords respectively D or L α- and β-amino acids.The regiochemistry of the cyclization has been studied, depending on the substituents of the double bond.Furthermore the absolute configuration of the newly introduced stereogenic center has been attributed on the basis of the 1H NMR spectra of the heterocycles.
- Amoroso, Rosa,Cardillo, Giuliana,Tomasini, Claudia,Tortoreto, Paola
-
p. 1082 - 1087
(2007/10/02)
-
- SYNTHESIS AND PROPERTIES OF β-SULTAMS
-
β-Sultames substituted in 2- and 3-position including bicyclic β-sultams were prepared and some of their reactions are reported.
- Koller, Wolfgang,Linkies, Adolf,Rehling, Herbert,Reuschling, Dieter
-
p. 2131 - 2134
(2007/10/02)
-
