Title

Environmentally friendly reactions: I. Efficient, catalytic, aerobic oxidation of alcohols with octahedral molecular sieves. II. New synthetic process for preparing 2,2,6,6-tetramethyl-4-oxopiperidine

Date of Completion

January 2003

Keywords

Chemistry, Inorganic|Chemistry, Organic

Degree

Ph.D.

Abstract

This research consists of two major parts and may result in an industrially useful application of catalysts. The first part involves the oxidation of alcohols with octahedral molecular sieves (OMS-2) in an environmentally friendly manner. Oxidation of alcohols is a very important process in industry and academia. Manganese oxides have been given a great deal of attention because of their catalytic properties and huge resources are available in deep-sea manganese nodules. The main goal of this study is to find a catalyst in the aerobic oxidation of alcohols using OMS-2. OMS-2 materials were tested as catalysts to promote the oxidation of various alcohols in an oxygen atmosphere, and these materials were modified to get the best results for alcohol oxidation. The modification of the catalyst and industrially useful reactions were also searched. ^ The second part concerns a process for the synthesis of 2,2,6,6-tetramethyl-4-oxopiperidine in a liquid phase in a single step at room temperature at ambient pressure. 2,2,6,6-tetramethyl-4-oxopiperidine, which is known as a triacetonamine (TAA), is an intermediate for drugs, and a new efficient photostabilizing agent for plastic products. One of the most commonly used procedures is as follows; Acetonine (2,2,4,4,6-pentamethyl-1,2,5,6-tetrahydropyrimidine) is made from acetone, ammonia and a catalyst at room temperature. After purification, acetonine is mixed with more than 6 equivalents of acetone and refluxed, giving TAA in the presence of Lewis acid. These two-step processes are complicated and require a purification process after the first step. Another process for the preparation of TAA involves the acid condensation of acetone with ammonia under pressure and reflux conditions in the presence of calcium or zinc chloride. The disadvantages are that this method uses a homogeneous catalyst and requires high pressures and temperatures. The purpose of this research is to find a new, easy and environmentally friendly method using a catalyst. Suitable catalysts are sought and optimum conditions are developed. ^