Cyclohexanone condensed phase reaction with

Although nylon intermediates are aliphatic, the main starting materials are aromatic hydrocarbons. In the earliest processes, phenol was hydrogenated (over nickel or palladium) to cyclohexanone/ol mixtures, known as KA oil , which gave adipic (hexanedioic) acid on oxidation with nitric acid. Half of this adipic acid was converted to the dinitrile, by vapour phase reaction with ammonia. Finally the dinitrile was hydrogenated to hexamethylenediamine (1,6-diaminohexane). Nylon-6,6 is produced by the condensation of essentially equimolar quantities of adipic acid and the diamine. 

The mixture is cooled in an ice bath, any sodium or sodium amide which may remain in the necks of the flask is scraped into the reaction mixture with a spatula, and enough water is added to dissolve the sodium bromide. The ether layer is separated and combined with five 100-ml. ether extracts of the aqueous phase, washed with 150 ml. of saturated sodium chloride solution, and dried over anhydrous sodium sulfate. The ether is removed by distillation, and the residue is fractionated carefully under reduced pressure through a 4-ft. heated column packed with glass helices and fitted with a total-condensation variable take-off head. The yield of 2-aUylcyclohexanone boiling at 90-92°/17 mm. is 153-174 g. (54-62%). In addition, 28-38 g. of unchanged cyclohexanone boiling at 51-52°/l7 mm., 15-35 g. of diallylcyclohexa-... 

Classical Aldol. Aldol reaction is an important reaction for creating carbon-carbon bonds. The condensation reactions of active methylene compounds such as acetophenone or cyclohexanone with aryl aldehydes under basic or acidic conditions gave good yields of aldols along with the dehydration compounds in water.237 The presence of surfactants led mainly to the dehydration reactions. The most common solvents for aldol reactions are ethanol, aqueous ethanol, and water.238 The two-phase system, aqueous sodium hydroxide-ether, has been found to be excellent for the condensation reactions of reactive aliphatic aldehydes.239... 

The lower reactivity of benzaldehyde with respect to acetaldehyde was found also in the vapour phase aldolisation over lithium phosphate [390]. Over the same catalyst, the reactivity order in the self-condensations of aldehydes could be estimated as CH3CHO > CH3CH2CHO (CH3)2-CHCHO. The reactivity of isobutyraldehyde in the self-condensation was almost undetectable, probably due to steric hindrance on the a-carbon, but this substance was able to react as a hydrogen acceptor with cyclohexanone. With propionaldehyde over a calcium hydroxide catalyst, a Cannizzaro-type reaction occurred to some extent simultaneously with the aldolisation [390]. This unexpected result was also recorded by other authors [391], who established that the tendency to aldolisation decreased, and the tendency to the Cannizzaro reaction increased, with... 

In addition to the products mentioned hitherto, the formation of various condensed products was also reported in the liquid phase and in solu-tion in addition, the formation of cyclohexanone pinacoP and caproic acid in cyclohexanol and water solutions, respectively, was observed. Moreover, aliphatic alcohols with carbon atom numbers equal to those of the original ketones were found in the liquid phase and also in solution It is probable that these products were formed by the interaction between the excited and the normal ketone molecules or in the reaction of the excited ketone with the solvent. These processes may be symbolized as... 

Dimethylamine hydrochloride (1 equivalent) was prepared by evaporation of a mixture of aqueous dimethylamine (45 g, 1.0 mol, as 25% aqueous solution) and excess concentrated hydrochloric acid under reduced pressure. To the solid residue was added an aqueous solution of the cyclohexanone (224 g, 2.0 mol) and formaldehyde (30 g, 1.0 mol, 40% aqueous solution). The two-phase mixture was heated carefully (reaction is exothermic) to boiling under a long reflux condenser, boiled for about 5 min, and then cooled to room temperature. Water (200 mL) was added, the layers separated, the aqueous layer saturated with sodium chloride, washed with ether (4 x 50 mL), and then made basic with 30% aqueous potassium hydroxide (1.3 equivalents). The Mannich base separated as a yellow upper layer with a strong amine odor. The layers were separated, the aqueous layer extracted with ether (5 x 100 mL), the combined organic layer and ether extracts dried over magnesium sulfate, and the solvent was distilled to provide the amino ketone (118 g, 70%). 

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