Influence of the solvent on the equilibrium of 4-carbomethoxy-1, 3-dithiacyclohexanones-5

1. The position of equilibrium of 4-carbomethoxy-1, 3-dithiacyclohexanone-5 (I), 2-methyl-4-carbomethoxy-1,3-dithiacyclohexanone-5 (II), and 2, 2-dimethyl-4-carbomethoxy-1, 3-dithiacyclohexane-5 (III) in acetonitrile, 50% aqueous dioxane, methanol, ethanol (fractional distillate), abs. ethanol, isobutanol, dioxane, and heptane was determined. 2. The ratio of the equilibrium constants of (I) and (II) does not depend on the nature of the solvent. © 1970 Consultants Bureau

A method for determining the position of tautomeric equilibrium solely from infrared and ultraviolet spectral data

A method was described for determining the position of equilibrium in tautomeric systems, using only data from IR and UV spectra. © 1969 Consultants Bureau

A study of the tautomerism of the N-alkyl-3-methoxycarbonyl-4-piperidinones and their hydrochlorides

The positions of the equilibria of N-alkyl-3-methoxycarbonyl-4-piperidinones in the liquid state, in water, in alcohols, and in CCl4 have been determined by IR and UV spectroscopy. It has been shown that Meyer's equation is not satisfied for them. This is due to the high steric requirements of the solvating electron pair of the nitrogen atom. On the basis of the fact that on passing from the methyl ester of cyclohexan-1-one-2-carboxylic acid to the N-alkyl-3-methoxycarbonyl-4-piperidones the position of the equilibrium in the liquid state and in CCl4 does not shift in the direction of the enol it is deduced that the spatial requirements of the free electron pair of the nitrogen atom do not appreciably exceed the steric requirements of the hydrogen atom. The IR and UV spectra of the chlorides of the N-alkyl-3-methoxycarbonyl-4-piperidinones in the solid state and in water and in alcohols are given. © 1971 Consultants Bureau

The IR and UV spectra of enol forms of N-butyl-4-cyano-2, 3-dioxopyrrolidine and N-butyl-4-carboethoxy-2, 3-dioxopyrrolidine

1. The five-membered chelate ring of enols of α-diketones and the six-membered chelate ring of β-cyanoketones, if it is formed, has a strength analogous to the intermolecular hydrogen bond. 2. A decrease in the conjugation in the quasiaromatic six-membered chelate ring of cyclic β-keto-esters with substituted five-membered rings is observed. © 1969 Consultants Bureau

A study of the tautomerism of the N-butyl-4(2)-methoxycarbonyl-pyrrolid-3-ones and their hydrochlorides

The tautomerism of N-butyl-2-methoxycarbonyl-4-methylpyrrolid-3-one (I), N-butyl-4-methoxycarbonylpyrrolid-3-one (II), N-butyl-4-methoxycarbonyl-2-methylpyrrolid-3-one (III), N-butyl-4-methoxycarbonylpyrrolid-3-one hydrochloride (IV), and N-butyl-4-methoxy-carbonyl-2-methylpyrrolid-3-one hydrochloride (V) has been studied by UV and IR spectroscopy. It has been found that the esters I-V are highly ionized in aqueous and ethanolic solutions at concentrations of 10-2-10-3 M. On passing from methyl cyclopentran-1-one-2-carboxylate to the esters II and III the position of the equilibrium in heptane and CCl4 shifts in the direction of the keto form. On passing from the esters II and III to the esters IV and V, the position of the equilibrium shifts in the direction of the enol. Meyer's relationship is not satisfied for the esters II and III, while it is satisfied for the esters IV and V. Hypotheses have been put forward on the causes of the phenomena mentioned. © 1972 Consultants Bureau

A method for determining the position of tautomeric equilibrium solely from infrared and ultraviolet spectral data

A method was described for determining the position of equilibrium in tautomeric systems, using only data from IR and UV spectra. © 1969 Consultants Bureau

Influence of the solvent on the equilibrium of 4-carbomethoxy-1, 3-dithiacyclohexanones-5

1. The position of equilibrium of 4-carbomethoxy-1, 3-dithiacyclohexanone-5 (I), 2-methyl-4-carbomethoxy-1,3-dithiacyclohexanone-5 (II), and 2, 2-dimethyl-4-carbomethoxy-1, 3-dithiacyclohexane-5 (III) in acetonitrile, 50% aqueous dioxane, methanol, ethanol (fractional distillate), abs. ethanol, isobutanol, dioxane, and heptane was determined. 2. The ratio of the equilibrium constants of (I) and (II) does not depend on the nature of the solvent. © 1970 Consultants Bureau

Board of Trustees Meeting, March 26, 1998

The agendas for meetings of the Johnson County Community College Board of Trustee