N-CYCLOHEXYLHYDROXYLAMINE

Preparation

In a three-necked, 50 ml flask equipped with a magnetic stirrer, thermo­meter, condenser with provision for the venting of hydrogen, and a serum cap, and containing 2.26 gm (0.02 mole) of cyclohexanone oxime at 0°C is added by means of a hypodermic syringe 17 ml of a 2 Μ solution of diborane in tetrahydrofuran at such a rate that the reaction temperature is always maintained below 10°C. After the addition has been completed, the reaction is continued for 4 hr at room temperature. Then the solvent is removed under reduced pressure and the flask's content is cooled to 0°C. By means of a syringe a few drops of 10% aqueous sodium hydroxide is added slowly.

CAUTION: Considerable heat may evolve at this point. In one case, a mild explosion has been reported.
Then a total of 10 ml of 10% aqueous sodium hydroxide is added. The reaction mixture is then refluxed for 1 hr and the product is separated from the reaction mixture by a 90 hr continuous extraction with pentane. The pentane solution is evaporated in a nitrogen stream to give a crude residue which sublimes at 60°C/1 mm Hg to afford 1.89 gm (82%), m.p. 140°C.

Synthesis Reference(s)

The Journal of Organic Chemistry, 54, p. 4026, 1989 DOI: 10.1021/jo00278a009

Raw materials

Preparation Products