Abstract: The present invention relates to an improved process for the oxidation of cyclohexane to adipic acid using air as an oxidant and a solid organotransition metal complex as a catalyst. The process comprises comprises reacting cyclohexane with air in the presence of a solid catalyst containing an encapsulated salen or substituted salen metal complex wherein some of the hydrogen atoms of the said organomanganese complex have been substituted by one or more electron withdrawing groups, at a temperature in the range of 20 to 120° C., at a pressure in the range of 50 to 1000 psi, in the presence or absence of solvents, with or without a promoter and isolating the adipic acid formed by conventional methods, such as filtration and centrifugation.