title: Synthesis of 6-substituted 2-phenacylpyridines from 2-(phenylethynyl)pyridine via isoxazolo[2,3-a]pyridinium salt.
abstract: When 2-(phenylethynyl)pyridine was oxidized, the formed N-oxide immediately cyclized at the ethynyl group to form isoxazolo[2,3-a]pyridinium salt. This salt underwent Reissert-Henze-type reactions with alcohol in the presence of a base to afford 6-substituted 2-phenacylpyridines, which are not easily synthesized through alternative procedures. When acetonitrile was used as a solvent, an amide functional group was introduced into the phenacylpyridine framework. Moreover, a hetero-atom at the 6-position facilitated the oxidation of the phenacyl group to afford α-diketones upon simple exposure of the reaction mixture to air.
authors: Faculty of Applied Sciences, Ton Duc Thang University, 19 Nguyen Huu Tho Street, Tan Phong Ward, District 7, Ho Chi Minh City, 700000, Vietnam.
authors: Song Thi
authors: ST
authors: Le
authors: Toshiki
authors: T
authors: Fujimoto
authors: Haruyasu
authors: H
authors: Asahara
authors: Nagatoshi
authors: N
authors: Nishiwaki