A NEW MICROWAVE REACTOR FOR BATCHWISE ORGANIC-SYNTHESIS

A laboratory-scale microwave batch reactor (MBR) has been developed for organic synthesis or kinetic studies on the 20-100 mt scale, with upper operating limits of 260 degrees C and 10 MPa (100 atm). The MBR complements a continuous microwave reactor which was the subject of a previous report from the authors' laboratory. Microwave-assisted organic reactions were conducted safely and conveniently in the MBR, for lengthy periods when required, and in volatile organic solvents. The use of water as a solvent for organic reactions was also explored. Examples include oxidation, elimination, esterifications, hydrolysis of a tertiary amide, etherification, isomerization, Hofmann elimination, alpha-iodination of a carboxylic acid, Claisen rearrangement, aminoreductone formation, and Wilgerodt reactions. Advantages of the new MBR include; the capability for rapid heating and quenching of reaction mixtures, minimal temperature gradients within the sample, and elimination of wall effects. Safety aspects have been discussed.