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Hell-Volhard-Zelinsky Reaction

Definition:

a-Halogenation of carboxylic acids in the presence of catalytic phosphorus, presumably involving the enol form of the intermediate acyl halide:

Frequency of appearance:

The periodicity of this reaction is not frequent enough to warrant a literature analysis.

Original reference:

C. Hell, Ber. 14, 891 (1881)

J. Volhard, Ann. 242, 141 (1887)

N. Zelinsky, Ber. 20, 2026 (1887).

Recent academic references:

Improved preparation of methyl 3-oxo-1-cyclohexene-1-carboxylate and its use in the synthesis of substituted 1,5-cyclodecadienes

Gordon L. Lange, John A. Otulakowski; J. Org. Chem.; 1982; 47(26); 5093-5096.

Kinetics of the acid-catalyzed .alpha.-bromination of aliphatic acids

Yoshiro Ogata, Toshiyuki Sugimoto; J. Org. Chem.; 1978; 43(19); 3684-3687.

Chlorination. II. Free radical vs. Hell-Volhard-Zelinsky chlorination of cyclohexanecarboxylic acid

John C. Little, et al.; J. Am. Chem. Soc.; 1969; 91(25); 7098-7103.

Recent process references:

N/A

Mechanism:

Scope and Limitations:

Catalyst: phosphorous tribromide, red phosphorous.^B
Carboxylic acids that can be easily enolizable (acyl halides, anhydridesaliphatic nitro compounds) do not need catalyst.A+B
May be difficult to obtain the mono halogenated product.^A+B
a -flourinated or a-iodinated carboxylic acids cannot be obtained by this method.B
a-iodination may be achieved in the presence of chlorosulfonic acid via a ketene.B

^Synonyms:

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