Ceralasertib is currently being evaluated in multiple phase I/II clinical trials for the treatment of cancer. Its structure, comprising a pyrimidine core decorated with a chiral morpholine, a cyclopropyl sulfoximine and an azaindole, makes it a challenging molecule to synthesize on a large scale. Several features of the medicinal chemistry and early development route make it unsuitable for the long-term commercial manufacture of the active pharmaceutical ingredient. We describe the investigation and development of a new and improved route which introduces the cyclopropyl moiety in a novel process from methyl 2,4-dibromobutyrate. Following construction of the pyrimidine ring, large-scale chlorination with phosphoryl chloride was performed with a safe and robust work-up. An S N Ar reaction required an innovative work-up to remove the unwanted regio-isomer, and then a Baeyer−Villiger monooxygenase enzyme was used to enable asymmetric sulfur oxidation to a sulfoxide. A safe and scalable metal-free sulfoximine formation was developed, and then optimization of a Suzuki reaction enabled the manufacture of high-quality ceralasertib with excellent control of impurities and an overall yield of 16%.
A significant proportion of genetic disease cases arise from truncation of proteins caused by premature termination codons. In eukaryotic cells some aminoglycosides cause readthrough of premature termination codons during protein translation. Inducing readthrough of these codons can potentially be of therapeutic value in the treatment of numerous genetic diseases. A significant drawback to the repeated use of aminoglycosides as treatments is the lack of balance between their readthrough efficacy and toxicity. The synthesis and biological testing of designer aminoglycoside compounds is documented herein. We disclose the implementation of a strategy to reduce cellular toxicity and maintain readthrough activity of a library of compounds by modification of the overall cationic charge of the aminoglycoside scaffold through ring I modifications.
A novel four-step bidirectional strategy
has been used to synthesize
the IJK fragment of the marine polyether natural product CTX3C from
a simple monocyclic precursor in a concise and efficient manner. The
four-step bidirectional sequence involves ring-closing metathesis,
alcohol oxidation, enol carbonate formation, and palladium-mediated
Tsuji–Trost allylation.
The I–L ring system found in all the Pacific ciguatoxins has been prepared from a tricyclic precursor in a highly stereoselective manner. Subtle differences in the reactivity of the enones present in the seven- and eight-membered rings of the tricyclic ether starting material have been exploited to allow selective protection of the enone in the eight-membered ring. Subsequent distereoselective allylation of the seven-membered ring has been accomplished by a palladium-mediated Tsuji-Trost reaction. The K-ring methyl and hydroxyl groups have been installed in a highly stereoselective manner by sequential conjugate reduction and enolate oxidation reactions. Ring L has been constructed by a use of a novel relay ring-closing metathesis reaction to complete the tetracyclic framework, which possesses the functionality necessary for elaboration of rings I and L and the introduction of ring M.
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