20599-01-3Relevant articles and documents
Diastereomeric Right- and Left-Handed Helical Structures with Fourteen (R)-Chiral Centers
Eto, Ryo,Oba, Makoto,Ueda, Atsushi,Uku, Tsubasa,Doi, Mitsunobu,Matsuo, Yosuke,Tanaka, Takashi,Demizu, Yosuke,Kurihara, Masaaki,Tanaka, Masakazu
, p. 18120 - 18124 (2017)
The relationship between chiral centers and the helical-screw control of their peptides has already been reported, but it has yet to be elucidated in detail. A chiral four-membered ring α,α-disubstituted α-amino acid with a (R,R)-butane-2,3-diol acetal moiety at the γ-position, but no α-chiral carbon, was synthesized. X-ray crystallographic analysis unambiguously revealed that its homo-chiral heptapeptide formed right-handed (P) and left-handed (M) 310-helical structures at a ratio of 1:1. They appeared to be enantiomeric at the peptide backbone, but diastereomeric with fourteen (R)-configuration chiral centers. Conformational analyses of homopeptides in solution also indicated that diastereomeric (P) and (M) helices existed at approximately equal amounts, with a slight preference toward right-handedness, and they quickly interchanged at room temperature. The circumstances of chiral centers are important for the control of their helical-screw direction.
Preparation method of baricitinib
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Page/Page column 10-12, (2018/07/06)
The invention discloses a preparation method of baricitinib and belongs to the technical field of drug preparation. The method comprises that 4-chloropyrrolopyrimidine as a starting raw material is subjected to amino protection, the product, hydrazine hydrate and acrolein undergo a one-pot displacement reaction and a cyclization reaction to produce an intermediate 4, a starting raw material 1, 3-dibromoacetone and ethylene glycol undergo a condensation reaction to produce an intermediate 5, the intermediate 5 and ethyl sulfonamide undergo a condensation reaction to produce an intermediate 6, the intermediate 6 and diethyl cyanomethylphosphonate undergo a reaction under action of a strong base to produce an intermediate 7, the intermediate 4 and the intermediate 7 undergo an addition reaction under the action of a catalyst, and the product undergoes a deprotection reaction to produce a desired product 1. The preparation method needs mild reaction conditions. The intermediate purification method is simple and easy, has a total yield of 40-55% and is suitable for industrial production.
NOVEL PHOSPHODI ESTERASE INHIBITORS
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Page/Page column 46, (2008/12/08)
The present invention relates to a compound according to formula I, wherein X, A, G, E, R1, R2, R3 are as shown herein; and pharmaceutically acceptable salts, hydrates, N-oxides or solvates hereof. The invention further re