Pyridine- N -oxide is the heterocyclic compound with the formula C 5 H 5 NO. This colourless, hygroscopic solid is the product of the oxidation of pyridine . It was originally prepared using peroxyacids as the oxidising agent. The compound is used infrequently as an oxidizing reagent in organic synthesis .
8-888: Kornblum may refer to: Science [ edit ] Kornblum oxidation , chemical reaction of a primary halide with dimethyl sulfoxide (DMSO) to form an aldehyde Kornblum–DeLaMare rearrangement , rearrangement reaction in which a primary or secondary organic peroxide is converted to the corresponding ketone and alcohol under base catalysis People [ edit ] Allan Kornblum (1938–2010), United States Magistrate Judge Allan Kornblum (1949–2014), poet and independent publisher John C. Kornblum (1943–2023), former US Ambassador to Germany Nathan Kornblum (1914–1993), organic chemist Ronald Kornblum (1933–2008), American coroner See also [ edit ] Boris Korenblum (1923–2011), Soviet-Israeli-American mathematician [REDACTED] Surname list This page lists people with
16-418: Is 124°, 7° wider than in pyridine. The oxidation of pyridine can be achieved with a number of peracids including peracetic acid and perbenzoic acid . Oxidation can also be effected by a modified Dakin reaction using a urea - hydrogen peroxide complex, and sodium perborate or, using methylrhenium trioxide ( CH 3 ReO 3 ) as catalyst, with sodium percarbonate . Pyridine N -oxide
24-451: Is different from Wikidata All set index articles Kornblum oxidation The Kornblum oxidation , named after Nathan Kornblum , is an organic oxidation reaction that converts alkyl halides and tosylates into carbonyl compounds. Similar to sulfonium-based oxidation of alcohols to aldehydes reactions, the Kornblum oxidation creates an alkoxysulphonium ion, which, in
32-549: Is five orders of magnitude less basic than pyridine: the pK a of protonated pyridine-N-oxide is 0.8. Protonated derivatives are isolable, e.g., [C 5 H 5 NOH]Cl. Further demonstrating its (feeble) basicity, pyridine-N-oxide also serves as a ligand in coordination chemistry . A host of transition metal complexes of pyridine-N-oxides are known. Treatment of the pyridine- N -oxide with phosphorus oxychloride gives 4- and 2-chloropyridines . The N-oxides of various pyridines are precursors to useful drugs: The compound
40-521: The surname Kornblum . If an internal link intending to refer to a specific person led you to this page, you may wish to change that link by adding the person's given name (s) to the link. Retrieved from " https://en.wikipedia.org/w/index.php?title=Kornblum&oldid=1191408752 " Categories : Surnames German-language surnames Surnames of Jewish origin Hidden categories: Articles with short description Short description
48-468: The presence of a base, such as triethylamine (Et 3 N), undergoes an elimination reaction to form the aldehyde or ketone . The first step is an S N 2 reaction , so it is subject to the usual leaving group limitations of that reaction. While iodides work well, even bromides are often not reactive enough to be displaced by the DMSO. However, using an additive such as silver tetrafluoroborate allows
56-412: The protocol, and using pyridine- N -oxide or similar reagents rather than DMSO. The Ganem oxidation built on this latter modification, expanding on the use of various N -oxide reagents. Pyridine-N-oxide The structure of pyridine-N-oxide is very similar to that of pyridine with respect to the parameters for the ring. The molecule is planar. The N-O distance is 1.34 Å. The C-N-C angle
64-422: The reaction to work on a wider range of substrates, as often seen for alkyl-halide substitutions, or they can be converted first to the corresponding alkyl tosylate. The reaction was initially limited to activated substrates, such as benzylic and α-halo ketones. To increase the range of viable substrates, Kornblum later added a preliminary conversion of the halide to a tosylate, which is a better leaving group, to
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