Cleavage of Saturated Fatty Acid Amides by Anhydrous Hydrogen Fluoride-Boron Trifluoride

Stephen S Hecht, Edward S. Rothman

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

N-Butylamides of long-chain, unbranched carboxylic acids undergo degradation, isomerization, and (in part) dimerization of the fragments when treated at 0-5° with liquid hydrogen fluoride saturated with boron trifluoride. The compounds studied were the N-n-butylamides of undecanoic, myristic, palmitic, and stearic acid. Two major classes of products were obtained: (1) saturated, branched N-n-butylamides and (2) saturated, branched N,N′-di-n-butyldiamides. The ratio of the former to the latter is 2:1. The products from N-n-butylundecanamide consist mainly of the following N-n-butylamides (relative proportions): 5-methylhexanamide (12.9%), 6-methylheptanamide (25.6%), 5-methylheptanamide (18.5%), 7-methyloctanamide (14.5%), and 6-methyloctanamide (6.5%). The branched diamides are predominantly of chain length Cu12-C15 (acid moiety). Similar results are obtained with N-n-butylmyristamide, N-n-butylpalmitamide, and N-n-butylstearamide when treated under the indicated reaction conditions; however, N-n-butylamides of acid moiety chain length shorter than C10 (e.g., the N-alkyloctanamide) are not affected. The probable mechanism of the reaction is discussed, and it is concluded that the inductive effect of the protonated amide group is important in determining the product distribution.

Original languageEnglish (US)
Pages (from-to)3733-3737
Number of pages5
JournalJournal of Organic Chemistry
Volume38
Issue number21
DOIs
StatePublished - Oct 1 1973
Externally publishedYes

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Hydrofluoric Acid
Chain length
Amides
Fatty Acids
Diamide
Acids
Dimerization
Isomerization
Carboxylic Acids
Degradation
Liquids
boron trifluoride
stearic acid

Cite this

Cleavage of Saturated Fatty Acid Amides by Anhydrous Hydrogen Fluoride-Boron Trifluoride. / Hecht, Stephen S; Rothman, Edward S.

In: Journal of Organic Chemistry, Vol. 38, No. 21, 01.10.1973, p. 3733-3737.

Research output: Contribution to journalArticle

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