149506-68-3Relevant academic research and scientific papers
Electrophilic fluorination of pyroglutamic acid derivatives: Application of substrate-dependent reactivity and diastereoselectivity to the synthesis of optically active 4-fluoroglutamic acids
Konas,Coward
, p. 8831 - 8842 (2007/10/03)
Electrophilic fluorination of enantiomerically pure 2-pyrrolidinones (4) derived from (L)-glutamic acid has been investigated as a method for the synthesis of single stereoisomers of 4-fluorinated glutamic acids. Reaction of the lactam enolate derived from 9 with NFSi results in a completely diastereoselective monofluorination reaction to yield the monocyclic trans-substituted α-fluoro lactam product 21. Unfortunately, a decreased kinetic acidity in 21 and other structurally related monofluorinated products renders them resistant to a second fluorination. In contrast, the bicyclic lactam 12 is readily difluorinated under the standard conditions described to yield the α,α-difluoro lactam 24. The difference in reactivity between the two types of related lactams is attributed mainly to the presence or lack of a steric interaction between the base used for deprotonation and the protecting group present in the pyrrolidinone substrates. This conclusion was reached based on analysis of the X-ray crystal structure of 21, molecular modeling, and experimental evidence. The key intermediates 21 and 24 are converted to (2S,4R)-4-fluoroglutamic acid and (2S)-4,4-difluoroglutamic acid, respectively.
Labelled fibrinogen receptor antagonists, the use thereof and processes for preparing them
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, (2008/06/13)
The invention relates to new labelled fibrinogen receptor antagonists which have an affinity for the receptor which is comparable to or greater than that of 125 I-fibrinogen and whose binding is not disrupted by foreign proteins.
Cyclic imino derivatives and pharmaceutical compositions containing them
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, (2008/06/13)
The invention relates to cyclic imino compounds which have, inter alia, valuable pharmacological properties, especially inhibitory effects on cell aggregation, pharmaceutical compositions which contain these compounds and processes for preparing them.
Cyclic imino derivatives, processes for preparing them and pharmaceutical compositions containing these compounds
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, (2008/06/13)
Cyclic imino derivatives of the formula wherein A, B, E, X1, X2 and Y are as defined herein, the stereoisomers, tautomers, mixtures and addition salts thereof, pharmaceutical compositions containing these compounds and processes for preparing them. The cyclic imino derivatives are useful as inhibitors of cell-cell and cell-matrix interactions, e.g., thrombocyte aggregation.
