83846-67-7Relevant academic research and scientific papers
Ketoserin intermediate and preparation method of ketoserin
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Paragraph 0045-0047, (2021/01/15)
The invention discloses a preparation method of a ketoserin intermediate 2, 3-dihydro-5H-oxazolo[2, 3-B]quinazoline-5-ketone and a preparation method of ketoserin, and the reaction equation of the preparation method of the ketoserin intermediate 2, 3-dihydro-5H-oxazolo[2, 3-B]quinazoline-5-ketone is shown in the specification: in the reaction, sodium carbonate and acetonitrile are used, no catalyst is added, inorganic salt is removed through hot filtration after the reaction, filtrate is evaporated to dryness, acetonitrile is recycled, and an intermediate 04, namely the ketoserin intermediate2, 3-dihydro-5H-oxazolo[2, 3-B]quinazoline-5-ketone, is obtained. The method is simple and convenient to operate, lower in cost, better in product character and more beneficial to synthesis of a finalproduct.
Ester vs. amide on folding: A case study with a 2-residue synthetic peptide
Vijayadas, Kuruppanthara N.,Nair, Roshna V.,Gawade, Rupesh L.,Kotmale, Amol S.,Prabhakaran, Panchami,Gonnade, Rajesh G.,Puranik, Vedavadi G.,Rajamohanan, Pattuparambil R.,Sanjayan, Gangadhar J.
supporting information, p. 8348 - 8356 (2013/12/04)
Although known for their inferiority as hydrogen-bonding acceptors when compared to amides, esters are often found at the C-terminus of peptides and synthetic oligomers (foldamers), presumably due to the synthetic readiness with which they are obtained using protected peptide coupling, deploying amino acid esters at the C-terminus. When the H-bonding interactions deviate from regularity at the termini, peptide chains tend to "fray apart". However, the individual contributions of C-terminal esters in causing peptide chain end-fraying goes often unnoticed, particularly due to diverse competing effects emanating from large peptide chains. Herein, we describe a striking case of a comparison of the individual contributions of C-terminal ester vs. amide carbonyl as a H-bonding acceptor in the folding of a peptide. A simple two-residue peptide fold has been used as a testing case to demonstrate that amide carbonyl is far superior to ester carbonyl in promoting peptide folding, alienating end-fraying. This finding would have a bearing on the fundamental understanding of the individual contributions of stabilizing/destabilizing non-covalent interactions in peptide folding.
