Rates of reaction of n-butanethiol with some conjugated heteroenoid compounds

Abstract

The reactions of substituted 3-benzal-2,4-pentanediones, ethyl benzalacetoacetates, diethyl benzalmalonates, benzalmalonamides, cinnamalmalononitriles, J3-nitrostyrenes, and J3-nitropropenylbenzenes with excess n-butanethiol go essentially to completion in 20% aqueous ethanolic solution buffered to pH 7. The second order rate constants derived from the reactions of meta-and para-substituted derivatives correlate well with Hammett o constants. The nature and conformation of the functional group cis to the phenyl group determines the extent to which ortho substituents hinder the reaction.

Metabolic fate of endogenous molecular damage: Urinary glutathione conjugates of DNA-derived base propenals as markers of inflammation

“…S1B) with a t 1/2 of ∼8 min, similar to the instability of 1a. A similar instability has been observed in 1, 4-butylthiol Michael-type adducts (21). In contrast, 2a was found to be stable (Fig.…”

Evaluation of 2‐benzylidenecyclohexanones and 2,6‐bis(benzylidene)cyclohexanones for antitumor and cytotoxic activity and as inhibitors of mitochondrial function in yeast: Metabolism studies of (E)‐2‐benzylidenecyclohexanone

“…The ether layer (1) was washed with sodium hydroxide solution (0.45 N, 2 X 10 ml) to give an aqueous phase (2). The aqueous phase (2) Feces-Feces (25.0 g) from the test rats were soaked in ether, ground in a mortar, and placed in a soxhlet extractor with ether (300 ml) for 66 hr.…”

Self‐Healing Polymer Networks Based on Reversible Michael Addition Reactions

“…Several studies have been reported, which demonstrated the reversible character of the thiol‐Michael addition . Already in the 1960s, the addition of n ‐butane thiol to conjugated heteroenoid compounds in aqueous ethanolic solution (pH 7) was found to be a fast and reversible reaction resulting in an equilibrium between the educts and the thiol‐ene adduct . Furthermore, Shi and Greaney described the addition of thiols (gluthathione) to different Michael acceptors (derivatives of ethacrynic acid) in water‐DMSO mixtures at pH 8 .…”

“…[28,29,32,33] Already in the 1960s, the addition of n-butane thiol to conjugated heteroenoid compounds in aqueous ethanolic solution (pH 7) was found to be a fast and reversible reaction resulting in an equilibrium between the educts and the thiol-ene adduct. [32] Furthermore, Shi and Greaney described the addition of thiols (gluthathione) to different Michael acceptors (derivatives of ethacrynic acid) in water-DMSO mixtures at pH 8. [29] Under these conditions, component exchange reactions were observed while an acidification (pH 4) locked the Michael addition.…”