Hass-Bender Oxidation

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The Hass-Bender oxidation , named after the chemists Henry B. Hass and Myron L. Bender , is a name reaction from the field of organic chemistry and was first described in 1949. The Hass-Bender oxidation enables the preparation of substituted benzaldehyde from substituted benzyl halides and 2-nitropropane .

Overview reaction

The Hass-Bender oxidation proceeds via an O -alkylation of 2-nitropropane by (possibly substituted) benzyl halides, followed by the elimination of a ketooxime :

Hass-Bender Oxidation Overview reaction V4

Reaction mechanism

The following reaction mechanism is described in the literature and is exemplified using benzyl chloride :

Hass-Bender oxidation mechanism V2

With sodium hydroxide solution , the salt of 2-nitropropane ( 1 ) is first formed with elimination of water . Compound 2 is formed via an O -alkylation with benzyl chloride . By eliminating the ketoxime ( 3 ), benzaldehyde ( 4 ) is finally formed .

Individual evidence

  1. ^ HB Hass and Myron L. Bender: The Reaction of Benzyl Halides with the Sodium Salt of 2-Nitropropane. A General Synthesis of Substituted Benzaldehydes In: J. Am. Chem. Soc. 71, 1949, pp. 1767-1769, doi: 10.1021 / ja01173a066 .
  2. Malcolm Bersohn: C versus O Alkylation in the Case of a Stable Cation In: J. Am. Chem. Soc. 83, 1961, pp. 2136-2138, doi: 10.1021 / ja01470a022 .
  3. Alfred Hassner and Irishi Namboothiri: Organic Synthesis Based on Name Reactions: A Practical Guide to 750 Transformations , Elsevier, 2012, ISBN 978-0-08-096630-4 , page 203rd
  4. ^ Zerong Wang: Comprehensive Organic Name Reactions and Reagents , Wiley, 2009, ISBN 978-0-471-70450-8 , pp. 1335-1337.