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• 108-94-1 cyclohexanone 
• 822-87-7 2-Chlorocyclohexanone 

Relevant academic research and scientific papers

Reactions of alicyclic ketones in carbon tetrachloride. I: The kinetics of the chlorination of cyclopentanone and cyclohexanone catalyzed by hydrogen chloride

The kinetics of the direct chlorination of cyclopentanone (cp) and cyclohexanone (ch) in carbon tetrachloride, catalyzed by hydrogen chloride, was studied.The rate of chlorination, measured by flow and stopped-flow techniques, is zero order in chlorine; the order in cp and ch increases from 1 at and of 0.01 M concentration to 2 at concentrations of 1 M.This is explained by self-association of the ketones in carbon tetrachloride solutions.The order in hydrogen chloride is 1.Since this compound is one of the products, the reaction is autocatalytic.Deuterium isotope effects and the kinetic data strongly point to a mechanism in which the oxygen-protonated monomeric ketone is α-carbon deprotonated in a rate-determining step.This step, which is catalyzed by the bases cp or ch, respectively, leads to the corresponding enol as intermediate.The enol is then chlorinated very rapidly.In addition to the chloro ketone, very reactive chloride anions are formed.A small fraction of these anions deprotonate α- or α'-carbon atoms of the oxygen-conjugate acid of the monochloro ketone.The remainder are captured by HCl to form energetically more favored Cl--(HCl)n complexes with n = 1, 2, or 3.This explains why, even at low conversions of the ketones, substantial amounts of the various dichloro isomers are formed in addition to monochloro products.A rate expression is derived, which excellently describes the experimentally obtained rates of chlorination of cp and ch over a range of reaction rates more than three decades.

Reactions of alicyclic ketones in carbon tetrachloride. II. Kinetics of the chlorination of 2-chlorocyclopentanone and 2-chlorocyclohexanone, catalyzed by hydrogen chloride

The kinetics of the direct chlorination of 2-chlorocyclopentanone (2-mccp) and 2-chlorocyclohexanone (2-mcch) in carbon tetrachloride, catalyzed by hydrogen chloride, were studied.Reaction products are all the possible 2,2-, 2,5-, and 2,6-dichloro compounds.The ratios depend on the concentrations of the monochloro compound and hydrogen chloride.Surprisingly, even at conversions of the monochloro compound as low as 2percent, 2,2,5-trichlorocyclopentanone and 2,2,6-trichlorocyclohexanone, respectively, are also formed.The chlorination of both monochloro ketones shows zero order in chlorine.The order in hydrogen chloride is 1.3.The order in 2-mccp and 2-mcch varies somewhat with the concentration of the ketone and was found to be roughly 1.7.The variation in reaction order is explained by a partial self-association of the ketones.The ketones act as substrates as well as basic catalysts in the rate-determining α- or α'-carbon deprotonation.General base catalysis is clearly demonstrated by a strong increase in the rate of chlorination of 2-mccp upon addition of cyclopentanone (cp) to the reaction mixture, which agrees with the mechanism as presented in a previous paper.Kinetic equations derived from the reaction models for the "separate" and "mixed" ketone chlorinations accurately describe the observed rates of the chlorination of 2-mccp and 2-mcch in the concentration range of 0.04 - 1.0 M.

PRACTICAL SYNTHESIS OF 2,2,5,5-TETRACHLORO-1,6-HEXANEDIOIC ACID, FROM TRANS-1,2-CYCLOHEXANEDIOL OR CYCLOHEXANONE, INVOLVING OXIDATION OF 3,3,6,6-TETRACHLORO-1,2-CYCLOHEXANEDIONE

Trans-1,2-cyclohexanediol was quantitatively converted into 3,3,6,6-tetrachloro-1,2-cyclohexanedione (2) by treatment with chlorine in dimethylformamide.The hydrate of the dione was oxidized by aqueous potassium permanganate to afford the title acid 1 in 91percent overall yield.An alternative low cost preparation was elaborated, providing 2 in 61-74percent yield starting from cyclohexanone in a three step procedure without isolation of intermediates.The reaction seqence involves substitution of α-dichloro- and trichlorocyclohexanones by sodium acetate in acetic acid and chlorination of the resulting 2-hydroxy- and 2-acetoxy-2-cyclohexenones in dimethylformamide.