Gibbs-Wohl-naphthalene oxidation

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The Gibbs-Wohl-naphthalene oxidation is a name reaction from the field of organic chemistry , which was first published in 1918 by the American chemists HD Gibbs (1872-1934) and C. Conover. With the help of this oxidation, phthalic anhydride can be synthesized from naphthalene .

history

Gibbs and Conover were assisted in researching the synthesis process in the 2nd decade of the 20th century by the American government . Phthalic anhydride was an important intermediate in the manufacture of dyes (e.g. indigo ) and drugs . The US government was keen to explore a new way to synthesize phthalic anhydride. The process common at the time (oxidation of naphthalene with sulfuric acid in the presence of mercury) was complex and costly. The United States imported in the early 20th century, their entire demand for phthalic anhydride from Germany.

Overview

Naphthalene is converted to phthalic anhydride by means of oxidation :

Gibbs Probably naphthalene oxidatio

Vanadium (V) oxide and oxygen , among others, are used as oxidizing agents .

Reaction mechanism

A suggestion for the reaction mechanism:

Gibbs-Wohl-naphthalene oxidation

Naphthalene ( 1 ) is converted to ( Z ) -2- (2-carboxyvinyl) benzoic acid ( 2 ) by adding vanadium (V) oxide and subsequent oxidation (e.g. with potassium permanganate ) . In this case, vanadium (III) oxide formed, which can be oxidized with oxygen again to vanadium (V) oxide. The vanadium (V) oxide oxidizes the ( Z ) -2- (2-carboxyvinyl) -benzoic acid ( 2 ) to 2-carboxybenzaldehyde ( 3 ). After a further oxidation with oxygen, the phthalic anhydride ( 4 ) is formed.

Practical meaning

The Gibbs-Wohl-naphthalene oxidation describes the leading industrial process for the production of phthalic anhydride.

Individual evidence

  1. ↑ HD Gibbs, C. Conover: Patent US 1,283,117 , filed February 17, 1917.
  2. ^ HD Gibbs, C. Conover: Patent US 1,284,888 , filed May 12, 1917.
  3. ^ A b C. R. Downs: Oxidation of Aromatic Hydrocarbons . In: Industrial & Engineering Chemistry . tape 32 , no. October 10 , 1940, p. 1294-1298 , doi : 10.1021 / ie50370a004 .
  4. ↑ HD Gibbs: Phthalic Anhydride. I — Introduction . In: Journal of Industrial & Engineering Chemistry . tape 11 , no. November 11 , 1919, pp. 1031-1032 , doi : 10.1021 / ie50119a010 .
  5. ↑ a b Z. Wang (Ed.): Comprehensive Organic Name Reactions and Reagents, 3 Volume Set . John Wiley & Sons, Hoboken, NJ 2009, ISBN 978-0-471-70450-8 , p. 1228.
  6. ↑ Z. Wang (Ed.): Comprehensive Organic Name Reactions and Reagents, 3 Volume Set . John Wiley & Sons, Hoboken, NJ 2009, ISBN 978-0-471-70450-8 , p. 1229.