Kinetics of the Reaction of Nitroalkanes with Methylenebispiperidine. A Study of the Mannich Reaction

J. E. Fernandez, Joanna S. Fowler, Stephen J. Glaros

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Pseudo-first-order kinetics are reported for the Mannich reaction of methylenebispiperidine with nitromethane, nitroethane, and 2-nitropropane in the solvents dioxane and dimethylforraamide. Evidence presented supports the act tautomer as the reactive form of the nitroalkane. A cyclic transition state is suggested for all three nitroalkanes in media of low dielectric constant, and for nitroethane and 2-nitropropane in media of moderately high (~25) dielectric constant. Under the latter conditions nitromethane probably reacts through a linear polar transition state. A rather large entropy of activation is found for the reaction of 2-nitropropane. While nitromethane and nitroethane fail to undergo a second alkylation with methylenebispiperidine in anhydrous media, the second alkylation occurs when water is present or when ethoxymethylpiperidine is used as reactant. These observations, along with rate studies employing 2-nitropropane and methylenebispiperidine in the presence of small amounts of water, point strongly to the N-hydroxymethylpiperidine as the intermediate in these Mannich reactions.

Original languageEnglish
Pages (from-to)2787-2791
Number of pages5
JournalJournal of Organic Chemistry
Volume30
Issue number8
DOIs
StatePublished - 1 Aug 1965
Externally publishedYes

Fingerprint

Dive into the research topics of 'Kinetics of the Reaction of Nitroalkanes with Methylenebispiperidine. A Study of the Mannich Reaction'. Together they form a unique fingerprint.

Cite this