Cyclohexane oxidation process

In a process for the oxidation of cyclohexane wherein the liquid cyclohexane and a gas containing molecular oxygen are continuously fed to a reactor operating at elevated temperature under pressure and wherein the liquid cyclohexane in absence of catalyst is converted to the extent of less than 5% to an oxidation product consisting essentially of cyclohexylhydroperoxide, cyclohexanol and cyclohexanone, and a liquid mixture of cyclohexane and the said oxidation product is continuously removed from the reactor, the improvement consisting essentially of conducting the oxidation in a two compartment reactor, the two compartments contacting each other to allow heat transfer between them, and releasing the entire reaction mixture in the first compartment in which the degree of conversion of cyclohexane is from 2 to 4% directly from the first compartment at a pressure in the range 8 to 50 bar absolute and a temperature in the range 150.degree. to 200.degree. C to the second compartment operating at a lower pressure in the range 2 to 5 bar absolute and a lower temperature in the range 115.degree. to 140.degree. C, whereby part of the cyclohexane is vaporized, and a liquid mixture of cyclohexane and oxidation product containing from 5 to 15% of oxidation product is