Zwitterionic uracil derivatives as potent GnRH receptor antagonists with improved pharmaceutical properties.
A novel series of potent zwitterionic uracil GnRH antagonists were discovered that showed reduced liability for CYP3A4 enzyme inhibition.
Regioselective direct C-H arylations of protected uracils. Synthesis of 5- and 6-aryluracil bases.
A new regioselective synthesis of 5- and 6-aryluracil bases based on direct C-H arylations of diverse 1,3-protected uracils has been developed. Benzyl-protected uracils were selected as the most practical in terms of stability during the arylation and facile cleavage of the benzyl groups. Pd-catalyzed C-H arylations in the absence of CuI gave preferentially 5-aryl-, whereas the reactions in the presence of CuI gave 6-aryl-1,3-dibenzyluracils. Final deprotection either by transfer hydrogenolysis over Pd/C or by treatment with BBr(3) gave the desired free arylated uracil bases in good yields.
Phloroglucinol derivatives from Hypericum japonicum.
The isolation and identification of a new phloroglucinol derivative (2), a diterpenol (4), together with the known compounds flavesone (1) and sarothralen B (3), from the aerial parts of Hypericum japonicum are reported. Their structures were established by extensive spectral analysis and the structure of (3) has also been confirmed by a single crystal X-ray determination.