Acylation of Nitronates: [3,3]-Sigmatropic Rearrangement of <i>in Situ</i> Generated <i>N</i>-Acyloxy,<i>N</i>-oxyenamines
作者:Aleksandr O. Kokuev、Yulia A. Antonova、Valentin S. Dorokhov、Ivan S. Golovanov、Yulia V. Nelyubina、Andrey A. Tabolin、Alexey Yu. Sukhorukov、Sema L. Ioffe
DOI:10.1021/acs.joc.8b01652
日期:2018.9.21
affords α-acyloxyoxime derivatives via an umpolung functionalization of the α-position. This transformation involves generation of hitherto unknown N-acyloxy,N-oxyenamines and their fast [3,3]-sigmatropicrearrangement driven by the cleavage of the weak N–O bond. The reaction has a broad scope, and it is regioselective in the case of nitronates possessing nonsymmetrically substituted α-positions. Application
Active compounds of Formula I are described:
wherein: R
1
and R
2
are each independently C1-C4 alkyl; or R
1
and R
2
together form a C2-C7 alkylene chain; and Z is a non-steroidal anti-inflammatory drug (NSAID); along with pharmaceutically acceptable salts and prodrug thereof, and methods of using the same.
Twenty-two nitroso compounds with cyano, acyloxy, or carbonyl groups in geminal position were prepared, eight of them for the first time. In the solid state these compounds dimerize to colorless azodioxides. Exceptions are the 4-nitrobenzoyloxynitroso compounds 7b, f, and g which form bright blue crystals. In vitro (Born test, collagen) considerable antiplatelet activity was observed in each class of compounds. Azodioxides with cyano groups in geminal position (3a, b) were most active (IC50 approximate to 10 mu M) suggesting the importance of strong electron withdrawing groups in geminal position to the azodioxide partial structure. When administered orally to rats (60 mg/kg) all compounds inhibited the thrombus formation in mesenteric arterioles and venules. The acetyloxy derivatives 5d and 5e were most active (18-21% inhibition in arterioles and 11-15% inhibition in venules). In aqueous media at 37 degrees C the cyanonitroso compound 3b and the benzoyloxynitroso compound 7a decomposed to nitric oxide and its reduced form nitrosohydrogen. This suggests that the above pharmacological effects are mediated by a NO dependent mechanism.
The Acylation of Salts of Secondary Nitroparaffins<sup>1</sup>