6952-53-0Relevant articles and documents
Synthesis of new cyclazines and 4,5-diaryl-1 H -pyrrol-3(2 H)-one units in discoipyrroles from indolizinone-DMAD cycloadducts
Kurian, Jais,Kannoth M, Muraleedharan
, p. 8832 - 8848 (2019/10/22)
The reaction of indolizinones with dimethyl acetylenedicarboxylate gave direct access to 3′,8a-dihydrocyclopenta[hi]indolizin-8a-ol and 1H-pyrrol-3(2H)-one in good yields. The former skeleton is a precursor to cyclazines with nitrogen on the periphery, a hitherto un-accessed 10-π system. Their formation involves initial [4 + 2] or [8 + 2] modes of cycloadditions; the retro-Diels Alder reaction of the [4 + 2] cycloadduct leads to 1H-pyrrol-3(2H)-one, whereas [8 + 2] addition followed by π-reorganization leads to the azatricyle. Analysis of substituent effects on product distribution showed that electron donating groups on the C3-aryl ring promote the formation of the azatricycle preponderantly. Treatment of one of these azatricycles (3c) with HBF4 led to the formation of the corresponding 10e-aromatic species which was detected by NMR spectroscopy. In addition, formation of the 1H-pyrrol-3(2H)-one skeleton through the normal retro-Diels Alder pathway was employed in the total synthesis of Discoipyrrole C, which is a new lead against lung cancer.
SUBSTITUTED AMINOTHIAZOLES AS INHIBITORS OF CANCERS, INCLUDING HEPATOCELLULAR CARCINOMA, AND AS INHIBITORS OF HEPATITIS VIRUS REPLICATION
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Paragraph 0140; 0141, (2013/04/24)
Pharmaceutical compositions of the invention are presented which comprise substiuted aminothiazoles derivatives. The substiuted aminothiazoles derivatives have a disease-modifying action in the treatment of diseases associated with unregulated cell growth. Such diseases include cancers such as hepatocellular carcinoma, and viral infections from a hepatitis virus.
Triplet states mediating hydrogen abstraction in 4-acylpyrimidines, 2-acylpyridines, 2-acylpyrazines, and 3-acylpyridazines
Prathapan, Sreedharan,Robinson, Kevin E.,Agosta, William C.
, p. 1838 - 1843 (2007/10/02)
Irradiation of 9 leads to hydrogen abstraction by N(1) and fragmentation to 8 from a triplet with ET ~78 kcal/mol. Irradiation of 2-acylpyridines (10) leads to abstraction by both nitrogen and oxygen (cf. eq 4), with the same Stern-Volmer kqτ for the two processes. Irradiation of 2-acylpyrazines (11) can lead to abstraction by either nitrogen (φ27 0.77 from 11b) or oxygen (φ11a 0.95 from 11f)- 3-Acylpyridazine 12d is unreactive on direct irradiation or triplet sensitization with sensitizer ET ~70 kcal/mol; it furnishes a small amount of 12a on sensitization by acetone. Ketone 18 is recovered unchanged from irradiation under all conditions used with 12d. These observations suggest a correlation between the photochemistry of each of these compounds and the energy of the nπ* triplet of the heteroaromatic ring. The nature of the excited state(s) responsible for hydrogen abstraction by nitrogen and oxygen in these ketones is discussed.