Selective Oxidation Of Alcohols And Oximes By Manganese And Chromium Under Solvent-free Conditions

Carbonyl compounds are important chemical intermediates, whichhave been widely applied in many different fields, such as pharmacy, agriculture,dyes and so on. For example hydroxybenzaldehyde, is used to synthesize theherbicide bromoxynil and hydroxyl dichlobenil, amoxicillin and antibacterialsynergist Trimethoprim （TMP）, vanillin and ethyl vanillin. But chemical industry hascaused environment pollution and resource waste. It is a hot issue to find the simplemethods and use less certain reagent to synthesize target products. So we studied theefficient and selective oxidation of alcohols and oximes under solvent-free conditionsand made two main conclusions as follows:1. The Efficient and selective oxidation of alcohols with CrO₃（Y=90%⁹8%） orMnO₂（Y=82%⁹6%） supported on kieselguhr in solvent-free conditions has highyield. Kieselguhr is not only the support but also a kind of catalyst, since it can give ahigher yield than the other supports under the same condition. This method is evenbetter than that under microwave irradiation. Which only oxidates alcohol toaldehyde.2. An environmentally benign method for the oxidation of oximes with KMnO₄（Y=82%⁹6%） and MnO₂（Y=82%⁹8%） supported on kieselguhr under solvent-freeconditions is also effective and affords high yield. Compared with the reportedmethods, the reaction can occur in simple, mild reaction conditions, and reduce theamount of oxidant and shorten the reaction time as well.