Cyclohexanenitrile

The checkers have used the dry, crude product directly in the conversion to 1,1 -a.zo-bis-1 -cyclohexanenitrile (see p. 16) with an over-all yield of 72% based upon cyclohexanone. 

The traditional method of oxidizing hydrazine derivatives makes use of halogens or hypohalites as oxidizing agents. The techniques range from the preparation of l,l -azobis(l-cyclohexanenitrile) by the addition of bromine to an alcoholic hydrochloric acid solution of the corresponding hydrazine [89], through the use of bromine water [90, 91] to oxidations with sodium hypo-bromite [64] or sodium hypochlorite [92]. 

POLYHYDROGEN FLUORIDE REAGENT 1-FLUORO-ADAMANTANE. Dichloroalkane synthesis is shown in cis-DI-CHLOROALKANES FROM EPOXIDES cis-1,2-DICHLORO-CYCLOHEXANE. Nitrile functionality can be introduced from a ketone, as in NITRILES FROM KETONES CYCLOHEXANENITRILE, or from a reactive diene, as shown in 2,3-DICYANOBUTADIENE AS A REACTIVE INTERMEDIATE BY in situ GENERATION FROM 1,2-DICYANO CYCLOBUTENE 2,3-DICYANO-1,4,4a,9a -TETRAHYDRO-FLUORENE. 

This reagent is useful for initiating radical reactions. Since it is a radical initiator, only small amounts are needed. For reactions at higher temperature, ACN (1,1 -azobis-1 -cyclohexanenitrile [2094-98-6]) has been suggested (see Example 2).1... 

Azo-bis-1 -cyclohexanenitrile has been prepared in a similar manner by Hartman.3 The method has been substantiated by Overberger, O Shaughnessy, and Shalit4 and is a modification of that used originally by Thiele and Heuser 5 for the synthesis of 2,2 -azo- is-isobutyronitrile. 

The hydrogenation of benzonitrile catalyzed by 21 afforded under 75 bar of H2 and at 140°C in THF a 90% conversion revealing a TOF of 180 h forming 66% dibenzylamine, 24% tribenzylamine, and 10% dibenzylimine within 1 h. The presence of EtsSiH as a co-catalyst improves the catalytic performance with respect to both activity and selectivity. When 25 equiv. of EtsSiH with respect to the rhenium catalyst was applied, the same reaction showed a conversion of 99% with a TOF of 396 h within 0.5 h forming 90% dibenzylamine, 4% tribenzylamine, and 6% dibenzylimine. The generality of the reaction was probed by applying the Re(I) catalysts 22-24 under the same conditions in the hydrogenation of 3-methyl-benzonitrile, thiophen-2-carbonitrile, cyclohexanenitrile, and benzyl nitrile (Scheme 27). 

The first step in our procedure for initiating the free-radical chain reaction is the homolysis of l,r-azobis[cyclohexanenitrile] (1), abbreviated as ABCN, to form nitrogen and the free radical 2 (Eq. 9.5). The rate of this reaction is sufficiently fast at 80-100 °C to generate enough chlorine atoms to initiate the chain process. The radical 2 then attacks sulfuryl chloride to generate chlorine atoms and SO2 according to Equations 9.6 and 9.7. The series of reactions depicted in Equations 9.S-9.7 comprise the initiation steps of the reaction. 

For certain types of radical reaction, AIBN may not always give optimal results. Keck and Burnett found in their synthesis of PGp2a that the introduction of the lower side chain, involving radical addition onto a B-stannyl enone, was inefficient when AIBN was used as initiator at 65 °C. By conducting the reaction in refluxing toluene (110°C), and replacing AIBN with the related IJ -Azobis-l-cyclohexanenitrile (ACN), a markedly better yield of the desired adduct was obtained (eq 10). ... 

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