Synthesis of sterically hindered 3-(azolyl)pyridines

Lukyanov, S. M.; Bliznets, Igor V.; Shorshnev, S. V.

doi:10.3998/ark.5550190.0010.403

Cited by 2 publications

(1 citation statement)

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“…Lukyanov et al described the synthesis of sterically hindered 3-(1,2,4-oxadiazol-3-yl)pyridines via a two-step process from substituted N -hydroxy-pyridine-3-carboximidamides and acyl chlorides using the room-temperature cyclization of O -acylamidoximes with TBAF in MeCN as the second step ( Scheme 4 ) [ 52 ]. Note that O -aroylamidoximes cyclized as well as O -alkanoylamidoximes.…”

Section: Base-induced Cyclodehydration Of O -Acyla...mentioning

confidence: 99%

Room Temperature Synthesis of Bioactive 1,2,4-Oxadiazoles

Baykov

Shetnev

Semenov

et al. 2023

IJMS

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1,2,4-Oxadiazole is an essential motif in drug discovery represented in many experimental, investigational, and marketed drugs. This review covers synthetic methods that allow the conversion of different types of organic compounds into 1,2,4-oxadiazole at ambient temperature and the practical application of the latter approaches for the preparation of pharmaceutically important molecules. The discussed methods are divided into three groups. The first combines two-stage protocols requiring the preliminary preparation of O-acylamidoximes followed by cyclization under the action of organic bases. The advantages of this route are its swiftness, high efficiency of the cyclization process, and uncomplicated work--up. However, it requires the preparation and isolation of O-acylamidoximes as a separate preliminary step. The second route is a one-pot synthesis of 1,2,4-oxadiazoles directly from amidoximes and various carboxyl derivatives or aldehydes in aprotic bipolar solvents (primarily DMSO) in the presence of inorganic bases. This recently proposed pathway proved to be highly efficient in the field of medicinal chemistry. The third group of methods consists of diverse oxidative cyclizations, and these reactions have found modest application in drug design thus far. It is noteworthy that the reviewed methods allow for obtaining 1,2,4-oxadiazoles with thermosensitive functions and expand the prospects of using the oxadiazole core as an amide- or ester-like linker in the design of bioactive compounds.

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Section: Base-induced Cyclodehydration Of O -Acyla...mentioning

confidence: 99%