Cyclohexanone oxime, reaction with

Reaction of cyclohexanone oxime (59) with phenylacetylene in the presence of KOH/ DMSO afforded Z-[l-(2-phenylvinyl)]-3-phenyl-4,5,6,7-tetrahydroindole (60) (equation 25) °. Transformation of 0-vinylacetophenone oxime (61) in the system f-BuOK/THF has been studied. The reaction at 60-65 °C afforded 2,4-diphenylpyrrole (62) and oligomeric products instead of the desired 2-phenylpyrrole (equation 26) . ... 

Effect of Reaction" Conditions of Cyclohexanone Oxime (116) with Dihaloethanes on the Ratio and Yield of Indoles 1 and 2 (Scheme 61) (82KGS1202)... 

The kinetics of the reaction of cyclohexanone oxime (1) with acetylene (Equation (1)) in MOH-DMSO under atmospheric pressure was studied and quantitative data on the effect of alkaline cations on the yields of 4,5,6,7-tetrahydroindole (2) and its N-vinyl derivative 3 as well as on the reaction selectivity were obtained (08DOC(423)66). 

N-Vinylpyrroles selectively add thiophenols under the conditions of free radical initiation to form p-adducts, N-(2-arylthioethyl)pyrroles (Scheme 2.200, Table 2.19) [668]. In analogous conditions, the reaction without an initiator leads to a mixture of p- (20%) and a-adduct (80%). Thiylation of a mixture of N-vinyl-4,5,6,7-tetrahydroindole (28.5%), 4,5,6,7-tetrahydroindole (61%), and cyclohexanone oxime both with and without the initiator selectively affords the a-adducts only. Probably, 4,5,6,7-tetrahydroindole and cyclohexanone oxime inhibit the radical addition thus hindering the p-adducts formation. Hence, owing to their increased acidity, thiophenols show a marked tendency to electrophilic addition to produce a-adducts [668]. 

Caprolactam [105-60-2] (2-oxohexamethyleiiiiriiQe, liexaliydro-2J -a2epin-2-one) is one of the most widely used chemical intermediates. However, almost all of the aimual production of 3.0 x 10 t is consumed as the monomer for nylon-6 fibers and plastics (see Fibers survey Polyamides, plastics). Cyclohexanone, which is the most common organic precursor of caprolactam, is made from benzene by either phenol hydrogenation or cyclohexane oxidation (see Cyclohexanoland cyclohexanone). Reaction with ammonia-derived hydroxjlamine forms cyclohexanone oxime, which undergoes molecular rearrangement to the seven-membered ring S-caprolactam. 

Cyclohexanone oxime is converted quantitatively to caprolactam by Beckmann rearrangement in the presence of oleum, which is of sufficient strength to consume the several percent water in the molten oxime. The reaction mass is neutralized with aqueous ammonia to a cmde caprolactam layer and a saturated solution of ammonium sulfate. Approximately 1.5 kg of the total 4.4 kg ammonium sulfate per kilogram of caprolactam is produced in this step. Purification is by multistage vacuum crystallization from aqueous solution in neatly quantitative yield. 

Toray. The photonitrosation of cyclohexane or PNC process results in the direct conversion of cyclohexane to cyclohexanone oxime hydrochloride by reaction with nitrosyl chloride in the presence of uv light (15) (see Photochemical technology). Beckmann rearrangement of the cyclohexanone oxime hydrochloride in oleum results in the evolution of HCl, which is recycled to form NOCl by reaction with nitrosylsulfuric acid. The latter is produced by conventional absorption of NO from ammonia oxidation in oleum. Neutralization of the rearrangement mass with ammonia yields 1.7 kg ammonium sulfate per kilogram of caprolactam. Purification is by vacuum distillation. The novel chemistry is as follows ... 

Reaction of hydroxylamine-0-sulfonic acid with cyclohexanone in alkaline solution can be shown to give pentamethyleneoxazirane (16). Compound 16 is an isomer of cyclohexanone oxime. It decomposes even at room temperature and thus cannot be prepared in a pure state. 

The TS-1 catalysed ammoximation of cyclohexanone with NH3/H2O2 is a new process (Romano et ai, 1990) for the production of cyclohexanone oxime, the precursor of caprolactam. In the existing process, the oxime is produced by reaction of cyclohexanone... 

Beckmann rearrangement of oxime is an acid catalysed reaction. The environmental problems associated with the use of sulphuric acid instigated interest to use number of solid acid catalysts [1], There are only scanty references about Lewis acid ion-exchanged MeAlPOs. Beyer et al. [2], Mihalyi et al. [3] and Mavrodinova et al. [4] already suggested the presence of Lewis acid metal ions as MO+ species in zeolites. The present study focussed the synthesis and characterisation of Fe3+, La3+ and Ce3+ ion-exchanged MAPO-36. The catalytic results of Beckmann rearrangement of cyclohexanone oxime over ion-exchanged catalysts are delineated in this article. 

The transformation of oximes to lactams (the Beckmann rearrangement) was one of the earliest such acid-catalyzed reactions to be reported with TS-1 (138) and TS-2 (247) catalysts. The rearrangement of cyclohexanone oxime to e-caprolactam proceeds with high selectivity in the presence of TS-1, with high catalyst stability (138,247). 

For the two aldehydes discussed in the previous section (R, R = H R = Me, R = Hep), the reaction is thermoneutral in the gas phase. Thermoneutrality would also be expected for ketones, but which ketone/oxime should be the standard for comparison In the gas phase there are two possibilities acetone/acetone oxime and cyclohexanone/cyclohexanone oxime. The latter pair may be assumed to be essentially strainless, or at least that their strain energies are very much the same. The assumption is borne out by substituting these two pairs into equation 23 (R, R = Me R R = — (CH2)5—) and finding that the enthalpy of reaction is only 1.2 kJ moE, essentially thermoneutral. Comparing the Cg species with the cyclohexyl species (RR = —(CH2)s- R /R = Me/Hex, Et/Pen, Pr/Bu), the enthalpies... 

When cyclohexanone oxime 6e was used as amination reagent, primary amines were obtained from phenylmagnesium bromide. Reaction of 6e with alkyl Grignard reagents gave aziridines, whereas reaction with phenyllithium gave aziridine and the addition product of phenyllithium to the imine (Scheme 57) 24. 

The industrial e-caprolactam processes with cyclohexanone oxime as intermediate product were recently reviewed . The catalytic gas-phase Beckmann rearrangement has great industrial interest. Since the process proposed by DuPont in 1938 the investigation on catalytic gas-phase Beckmann rearrangement has been investigated, and a large variety of catalysts have been tested for the reaction. 

To a vigorously stirred suspension of 54.5 gm (0.3 mole) of TV-bromosuccini-mide in 150 ml of water, cooled to 10°C with an ice bath, is rapidly added a solution consisting of 11.3 gm (0.1 mole) of cyclohexanone oxime, 25.3 gm (0.3 mole) of sodium bicarbonate, and 150 ml of water over a 15 min period, while maintaining the reaction temperature at 10°C. 

In conclusion, decrease in cyclohexanone oxime yield and caprolactam selectivity with time on stream is a major factor in the use of boria on alumina catalyst in the rearrangement reaction. Coke deposition and basic by-product adsorption have been suggested as a means of deactivation. In addition the conversion of water soluble boron, which is selective to lactam formation, to an amorphous water insoluble boron species is another factor that can account for the catalyst deactivation. 

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